I've learned who to ignore and whose opinions to value. I've learned a lot about life, people's ideas, and what people are angry about. I learned that P&N is a place to generally avoid.
I've learned about ever single phishing, Nigerian, and ebay scam... multiple times each.
I've learned that there are a lot of people with no clue how to react to things their girlfriends have done, or how to attract a girlfriend in the first place.
I've gotten a lot of help in making car repairs.
It's been reinforced for me that a lot of people take better care of their cars than themselves.
I've heard every possible joke, read amusing news stories, read shocking news story, and visited weird/interesting/entertaining website on the internet long before anyone else I know... (example: 2 months ago, I was forced to show some coworkers "endofworld.swf" who had never seen it before). Better yet, is when my coworkers/friends are bewildered when I can bring one of these up during a casual conversation. "I can't believe something like that has never caused an accident." "Well, actually, there was an accident in Colorado about 2 weeks ago caused by that. 2 people were killed." "How do you know these things?"
I've learned how to awe some of my coworkers when they make comments like, "I have to drive to Buffalo to get new ink cartridges for my printer this weekend" with responses like "circuit city has xxxmodel of printer on sale for $xx.xx with a $30 rebate. Grab an ad while you're up in Buffalo, drive over to Compusa, have them pricematch CC's listed price, Compusa will also deduct the rebate; it works out to $14.92 out the door." "Ugghhhhh, how do you know these things??"