When I was 18 & I was just about to start college I decided that I'd outgrown the comic book collection that I'd spent almost nine years building. I had about 5000 comics. The most valuable of which was my early Marvel comics. I had complete or near-complete runs of titles like AMAZING SPIDER-MAN, FANTASTIC FOUR, THE AVENGERS, UNCANNY X-MEN, DAREDEVIL, THE HULK & so on. All of which were worth tens of thousands of dollars.
Anyhow, I became obsessed with the idea that I needed a new car for college & the quickest, easiest way for me to reach that goal was to sell off my comic collection for the cash for the new car. But when I talked to my parents about it they tried like hell to talk me out of it because they knew how much my collection was worth & that it was only going to increase in value. Plus, they knew that I'd wind up regretting it. New car or not.
So, long story short. I didn't listen to my parents & because I was in a hurry to get that new car, I sold my collection to a local dealer who only gave me about a quarter of what it was worth. So, I sacrificed nearly a decade of love & effort that went into building that collection for the quick fix of getting the car before classes started at college. Something that I began to regret after only about a month. It took that amount of time for me to realize that I'd made a bad, hasty decision because my student loans & grants came in & I could have just used them for the car.
I thought about beginning a new comic collection but I just couldn't do it because it would never be as good as what I had. So, I went for a couple of decades without even looking at a comic book. Then one day I decided to go to my local comic shop & begin a new collection. But this one with much more modest goals because all those comics that I used to have had skyrocketed up in value over the years. That collection that I sold for a few thousand bucks would be worth enough to purchase a very nice house. And then some. So, I just focused on a few titles & certain runs of issues in eventually building up the 3000 book collection that I now own.
Actually, now that I've written this whole thing I've realized that it doesn't really fit the theme of the thread. It's far more of a biggest regret thread. But, what the hell, I'll still post it.