Why does one coin type appeal to a collector, while a similar denomination or design leaves him disinterested?

Recently I brought a large group of coins home from the bank for a weekend visit. While looking through the collection, I began to notice what seems to me, at least, to be a bit of an oddity.

And that oddity is my collecting preferences.

This is what I noticed:

I love Barber Dimes and Quarters, but have no interest in the Half. I own but one for my type set.

I am an enthusiastic collector of Seated Liberty H-Dimes, Dimes, Twenty Cents, and Halves. Quarters- No interest other than the type set.

How can this be explained? These groupings have similar, if not identical designs. The size doesn't appear to be a key for me.

I don't understand my own tastes!!

I'm crazy for Buffalo Nickels; Liberty Nickels, however, ...couldn't care less!

From my earliest collecting days, some 34 years ago, I sought out and purchased Washington Quarters, Franklin Halves, and Rooseveldt Dimes; along with Mercury Dimes, Walking Liberty Halves, and Jefferson Nickels. My interest in the first 3 coin types has waned significantly, to the point of having almost no interest. While I remain quite interested in the last 3. Rationale- I have no idea.

Please tell me that I am not the only irrational collector out there!!! Have others of you had similar experiences? If anyone has an explanation for what appeals and doesn't appeal to a collector at any point in time, I would love to hear it.