I'll do a better reply than my first, but select few describes VERY few collections of the folks on this board based on my experience over almost 10 years reading posts here.
I love knives. I love to fondle, or what some on the "porch" call "coon fingerin' " them. I enjoy the beauty of them, the craftsmanship, the quality.
Some knives just make you want to fondle them, others just don't do it for me.
My AG Russell (RIP) Acies, for instance. That knife just has the feel. It's a beauty, it functions flawlessly, it feels great to the touch. It just makes you feel good to have it, not to mention use it on a regular basis.
I also love Zero Tolerance knives, as I think they are one of the best values for the dollar in the business today - great quality and priced in the ballpark, particularly if you wait and get a model after the initial collectors furor calms down. Thus I have a large collection of Zero Tolerance knives which I love to carry and use in a rotation.
Then sometimes a knife just calls out to you. Why do I own a Busse WTF? Well - if you hold one in your hands and don't get a big, stupid grin on your face, then maybe you wouldn't want one, but everyone that I have handed that knife to gets the BSG-face. Is it a practical knife? No - not why I bought it. It just called out to me.
Same with several of the knives and guns I own.
Sometimes you get to know a maker, maybe because he or she lives in your area, and you want to patronize them and their products. I have many more JK Handmade Knives than I could ever put to good use, but I enjoy them and owning them and rotating them into use around the house and yard.
I am now, though, at the point in my collecting where I am selling off some of the knives that I don't use or that I don't rotate into my pocket, or that I just want to liquidate so I can buy something else. I think I have invested enough that now, heading into retirement, I will use proceeds from sales to fund new purchases more as a rule than the exception.
I have done some of that recently, and doing this (selling to buy) has been a refreshing addition to the hobby of collecting, particularly here on BF where I know most of the people and can feel comfortable with the dealings. It is adding to the enjoyment, and I am getting to fondle some knives that I didn't buy when new due to budgetary concerns.
I apologize for the wall of text, but the question deserved a little thought and a decent reply.
best regards
mqqn