What is the most important lesson you've learned through collecting?

[Exhibitman]

Many interesting thoughts in this thread but they are all 'growed up' ones. I found the most profound lessons I learned from collecting were learned as a kid:

1: Negotiations 101: Card collecting was great preparation for business life. I got ripped off quite a bit when I first started collecting. A couple of older kids in my neighborhood took advantage of my naivete as a 6-9 year old. But those were early, cheap lessons in the psychology and the nuts and bolts of deal making: how to maintain a poker face, how to facilitate a negotiation, bundling items for trade or sale, how to approach discounting, etc. By the time I was a tween I was a card shark, so to speak, and by the time I got to professional practice as a lawyer, analyzing and negotiating settlements in civil litigation was second nature to me because of all the negotiating I did as a kid card collector.

2: The value of information: I devoured everything I could find on cards and collecting. As a result I developed better knowledge of rare and esoteric issues than many others, even dealers. One of the reasons I've always gravitated to oddball issues is that relative information advantage. It is one reason why I spend so much time at the National going through random accumulations of stuff: there's gold in them thar piles, if you know how to look at them. That lesson has served me well in life too.

3: STFU and listen: You have two ears and two eyes and one mouth, so you should probably speak 20% of the time and listen and watch 80% of the time. People will reveal so much about themselves, if you shut your cakehole and pay attention.

4: When it comes to old stuff, don't just assume something is trash: a variant on information value. There have been quite a few times in my collecting life that I have stumbled across something that isn't in my collecting wheelhouse but that seemed interesting and worth saving, and I have rarely regretting saving it. My greatest find was literally saved from the garbage: I salvaged thousands of pieces of Academy Awards memorabilia from the trash when I was hired to clear out 50 or so old file cabinets at my father's public relations company during spring break one year in college. I didn't even know there was a market for the stuff but it was so cool that I kept everything that looked interesting, and selling it over the years paid for a lot of baseball cards.

5: Your word is all you have: should be self-explanatory but unfortunately isn't. You have one reputation so you best not destroy it with shady practices.