After a hard or stressful day, it can be easy for your brain to just give up. Personally, it's like I have a reservoir that holds my ability to think, and once that reservoir drains, then my IQ drops about 40 points. What I'm trying to say is, I have to work really hard to effectively allocate my thinking power. That dumb thing you heard me say earlier? That was completely intentional, otherwise I wouldn't remember how to drive my car home. It's all about balance.
Here are some people that understand the struggle of thinking things through.