Humanity won't recoverwww.youtube.com/watch?v=4ERbC7JyCfU&featu...
This is an old video, but it simply explains who complicated the world is now. Something that we think is so simple, like a pencil, is incredibly complex. The knowledge involved in making the rubber eraser is a fairly high knowledge of chemistry that the average human does not understand.
If the world ever collapses as we know it, whether by a man-made catastrophic event or a global natural disaster, the odds that enough people with the basic knowledge to restore what will be lost is very slim.
That being said, science was discovered once, it could be discovered again. Size and scale of an extinction even is key really. Depending on the mix of survivors, it could work, but it would have to be an awesome mix of scientists and skilled laborers.
But that's just what I think.