I am going to be a major difference-of-opinion poster on this one.
The majority of my thoughts are in the attachments. The first one addresses the time-regression aspect that usually comes up in these types of discussions. It directly addresses this thread topic. It is also included in the second attachment. A really long, rambling collection of many of my posts that in some way relate to this thread. It is a WIP, and as such, there is a great deal of duplication, as I copied over many things from many earlier articles, many of which contained included information from even earlier combinations. I have not had a chance to work on it in a long time, so feel free to scan through anything that is duplicated, or that does not hold any interest.
But I want to add a few things that I never did get around to putting down anywhere else.
On electrical/electronic aspects:
While the infrastructure to produce new items (radios, computers, large motors, large HD batteries, etc.) will be lost for some time, the information to produce them will not likely be lost. At least, if I accomplish one of my life goals, there will be thousands, and in many cases, millions of the items still around in usable condition for many months to years. And many of those can be, and will be kept in operation, or put back into operation, and used to great effect. Perhaps even more so than some are now. For instance, a smart phone, which is basically a phone for the most part, and used as such by most people, will become an extremely useful data and information storage device that is portable, and has many other useful features. From a calculator to a full computer more capable than many personal computers produced prior to the mid 1990s, capable of spreadsheet operations, and a whole multitude of other activities that will make life in the PAW much easier and productive.
While there will not likely be the world wide internet as we now know it, there are several ways to link the various computer systems and other electronic systems together over long distances so information and processing can be shared. It will likely be several weeks to many months before the systems are in wide use, but I believe they will be. I know Amateur radio operators that have the capability now.
On medical aspects:
Yes, we will not have the capability for most of the very high technology/high infrastructure dependent medical advances that can save lives, and prolong life, despite extremely complex and serious medical conditions. To put it bluntly, there will be many deaths in the aftermath of an event that destroys or limits current medical infrastructure. But afterwards, knowing that some things will be fatal, or people will never fully recover from some things that they now can, medical technology and practice will continue to do what can be done to save those that can be with what is available, and provide the best quality of life that can be provided. And while super drugs and other pharmaceuticals will not be available, many will not be needed, as the problems they help correct will not occur anyway, as those at risk will be dead from other causes, or due to an enforced better diet and exercise environment, will not have nearly as severe a problem as they would living the lifestyle that we do now.
And while even some of the earliest medical treatment advances may not be available for a long time, the medical profession, and the alternative medical professions have learned a great deal about how to treat the survivable problems without using some of the items modern technology allows us to create. Not only are some of the 'old' treatments still just as effective as they ever were, many new ones have been developed, and even more importantly, shared due to our current communications technology. And with enhanced growing systems that will still be available, regional and area products that were only available in limited locations can now be grown almost anywhere, so the full range of non-technological treatments will be available, once things settle down, and people are again growing and producing items beyond what is needed for immediate personal survival. Not to mention, there are other items that do not depend on plants that are now used with much more effect given the widespread knowledge of their existence, and the ability to produce them.
On general technology aspects:
While some will not be able to use much of our current technology, there will be many that will be able to, at least in some areas. The equipment will still exist, the skills will still exist, at least for a while, and as people see the needs and possibilities, new ways to combine old and new technology will be developed to give nearly the same results as the newest technology before the event did. Possibly not as quickly, but still highly effective.
One example. CNC machining. Both for wood and metal projects. Modern technology has given us very powerful motors that are small, and can be moved on transport mechanisms to do very precise work. With that tech available, it is, of course, used. But the same stepper motors that require very little electrical power can move the work table almost as easily as they can a cutter head that takes advantage of the powerful motors, using flexible cable. But if you make the cutter head fixed, driven not by a small powerful electric motor, but a stationary engine (solar powered Stirling cycle or stationary wood gas engine) using a jack-shaft drive system, with just a small amount of electrical power the same stepper motors can be controlled by a tiny PI3b computer to move the work table. You still have a CNC device, just using a combination of old and new tech. And that is just one example. There are many more that I can think of, and there are people out there much smarter and inventive than I am.
My main point, however, which is stated more fully in the first attachment, is that we will not, literally cannot, revert to an earlier time. We will use much of that earlier technology, with new technology enhancements, but the infrastructure that existed in those earlier times simply will not be there when the current infrastructure is lost. People will not be able to get goods, tools, foods, raw materials, and many other things that were just as available in those days, that our modern set of goods, tools, foods, raw materials, and many other things are to us now. The entire production and transport infrastructure around the world will cease to exist, and the 1800s, or 1900s, or 1700s, or 1600s versions will not suddenly appear. We will develop them again, and will use some of the newer technology to provide other alternatives, but we will not have access to very much that is not already in our area of operations. The colonists had a huge support structure behind them when they began coming to the New World. They had manufactured axes and saws. They had printing equipment. They had paper. They had rope and other cordage. They had metal knives. They had cotton from Egypt. They had silk from China. They had guns from England and Germany. It all came over using the infrastructure of the time. Without that infrastructure, the colonists would not have made it. As evidenced by some of the groups that did not make, due to the failure to get the support from England they required.
So, I believe we will be living a 21st century lifestyle, using technology from the most recent to the most ancient, but we will not be living an 1800s lifestyle.
Just my opinion.