Time...

The only reason for time is so that everything doesn't happen at once.
- Albert Einstein

That is an extremely simple and at the same time extremely profound statement. But in order to get complete grasp of this, unfortunately, you need to understand (atleast) special theory of relativity.
This link can help biginners - http://conduit9sr.tripod.com/SR1.html

The watch in the pic is mine :)

String Theory...

The pic is guitar and its strings :)