Haim, this was a bad year for me as I had no main system for at least half the year. So I am playing catchup (no pun intended) but in reality in a typical year I never would listen to everything that comes in 100% but probably I listen to more hours of music than the equivalent hours on the new music coming in. The reason is that I get stuck on certain music and can listen to one CD for weeks on end. The good news is that CD's don't expire (at least I hope not). While new stuff is coming in I may at the time be listening to something I bought 10 or 20 or 30 years ago for the first time.
This year also showed me how many mistakes I've made. In the past, Amazon would remove an item I just purchased. For some reason, this year it stopped doing this and so there are many things that I purchased multiple copies of. The worst one was Hewitt's Beethoven Piano Sonatas Vol. 6. I now have three copies. (and I don't really like Hewitt's Beethoven). And I think I also have two copies of Benjamin Grosvenor Homages. So I had to kick myself a couple of times but surprisingly it is rare that this happens considering the volume I have to manage.
I am a visual person so often I get confused when record companies reissue something with a different cover. I hate them for that. Then I sometimes can't remember if I bought something already or just wanted to buy something. Did I see it here when someone else listened to something I wanted or was it just in my Wish Lists which probably has 4 or 5,000 items in them.
Yes, there are probably lots of duds but I never toss things and give everything a second chance. Time and mood is always changing I think I have every CD / LP / DVD / Bluray / VHS / Book that I have ever bought in my life. I guess I like to collect things and have a library that I can see and touch.