Agree, in general, people over-think a lot, and aren't "just doing things" enough, the world would be a better place if people acted more, over-think less.
With that said, some decisions are more long-lasting and have a greater impact than others. I'm another child-less person, mainly because I guess I'm selfish enough to enjoy my life with my wife exactly like it is, and she agrees, but also because I know that if we have a kid, then that's not something you can walk back on exactly, he/she/it/them are there, forever now. Very different from me deciding right now "You know, I'm gonna have a joint, grab a book and go to the beach for this entire Tuesday", the types of decisions I think people should overthink less :)