Some aspects of the modern day...
...are scary as all get out! You're very right. If Armageddon came tomorrow and we had to rebuild, few of us have the requisite knowledge to make even a dent in what we'd need to do so. You have diabetes? Forget insulin. You can't see without glasses? Forget it. You want to keep a journal? Try cave walls.
We have become technology heavy to the point that survival after Armageddon will be only for the strong, the healthy and those with Green Thumbs.