I was headed that way. At one time I had about 40 handguns, a dozen 22 rifles...and several com-bloc surplus rifles.
One day I looked in the safe trying to decide which one I wanted to shoot today and realized I was being silly. How many do I really want? I knew for a fact I had at least one, someone else really wanted to fill a spot in his collection. He had offered me good money for it.
I contacted him and sold that one to him. Then over time, I sold off most of the rest. A period of "personal economic downturn" helped a lot, but it was easier than I thought it would be. I actually had just as much fun selling them as I did buying them.
I also came to the realization that it was the hunt for the gun I enjoyed, even more than I did having the gun.
These days, I've got a dozen or so total. I'll still see something I can't live without, but I generally end up selling or trading one I've already lost interest in, but it's a lot easier to look at one, think I HAD one like that" and move on.
And no, I don't mean to imply that I think everyone should do what I did.