Just a thought...
I think the #1 thing we can all do to make life a bit more simple is this:
If someone asks you something to which you do not know the answer... just say you do not know the answer.
I am growing very tired of people who just want to give me an answer and do not actually care if it is right or not. If I wanted a guess or a blatently wrong answer, I would have come up with that myself and not asked in the beginning!
Seriously, consider it -- I'll bet you do it way more than you think.