Done it before but not when I was upset. I type up something that I deem to be intellectually stimulating, then I realise that MPGH is made up of 12-14 yr olds so I delete it all and ask everyone how their day was. Quite fustrating really.
Story of my life. Write down a long complex paragraph only to realize the intended audience has neither the intellect nor maturity to properly respond.
It's perfectly normal, people do it all the time. Just like my thread, sometimes writing it out just can relieve frustration. You dig up all the facts, look at it in hindsight, and everything becomes crystal clear.
Posting it in general however is pretty dumb, even though I did it, it's full of idiots. Most of the time you get spammers and retards, but there are some intelligent people in this section. The few people here that do actually use their brain instead of mindlessly +1ing things can be helpful. Sometimes people just need to talk things out.