Chuck-
In a major way I have done that. I think it is a good thing. Short of the largely philosophical instant before we destroy something in our possession, we own nothing. We can own nothing we cannot take with us when we die, meaning we can own no thing.
Look at one of your older firearms and ask how many others called that gun "theirs". We are simply custodians of these things. If you have a very nice firearm, but you do not use or enjoy it any longer, why keep it and deny another of the joys of ownership? Why not sell it and purchase a firearm you really want and will enjoy?
Most recently, had I not sold my Sig 225 6 months ago(which I did not shoot very well and did not particularly enjoy) I would not now have my Fox Sterlingworth (an impulse purchase from my friend's table at a gun show). If I had not purchased that Fox, I would not have gotten the bug and purchased three more shotguns and over a thousand rounds of shotgun shells and spent countless hours enjoying and shooting these guns with friends and making new friends. Life is short, enjoy it.
Doug