It feels good to be completely self-reliant. Sure, it's not a good idea to take on projects that you know are totally over your head, but if we never stretched ourselves a little, we'd never learn and grow as people. Sometimes these learning opportunities are forced upon us, often accompanied with someone else's incompetence and our own justified, blinding rage.
For example, when the contractor calls and says "sorry I can't be there for another 3 weeks, and it'll cost 10,000 more than I quoted you," but you say "dude, the pipe has literally burst and all my commissioned self-portraits of me as a space man are getting soaked in grey water" it makes the decision to buy a monkey wrench and start reading manuals that much easier.
So here are some times that people found themselves in situations where the most simple and direct way to solve a problem was with their own two hands. And for some times people left things up to chance, here are people's "screw it, I'll deal with it later" moments.