I think I'm with you Marakanetz-I like to challenge myself musically.
I really cannot tell straight off the bat (not unless it really turns my stomach but that is usually stuff I find really derivative)wether I will like a piece of music or not.
In fact it takes some time for me to make a definitive decision about any new music(obscure or mainstream) sometimes I think I'm going to love something but that instant appeal can fade into mediocrity.
Of course as you grow older you understand better as your knowledge widens,if you continue to listen and to expand your tastes.
The 14 year old me would not have considered listening to jazz,now I'm a big fan but there is so much to take in.
One thing I find that proves your knowledge has expanded is if you listen to some music you loved back in your teenage years( or a decent distance back) and haven't played it for a long time,you'll find you will hear a lot of influences in it you've never heard before, even though you know the music really well...............
I remember vividly being about 14 and hearing Led Zep 3 for the first time-it seemed like the weirdest thing I'd ever heard,in fact the first few listens just didn't register at all,some 24 years later I can't imagine how that could ever have been, but it was.
So everything is relative.
My biggest problem now is my tastes are so eclectic that finding the time is the biggest problem,my collection grows and grows.
The other problem in the contemporary popular/rock field for me is that I am very aware of most of the reference points,that can get in the way when listening,you can dismiss stuff unfairly and without repeated listens.
As for difficult stuff, if you take a band like Autchere,(pretty harsh electronica),I have about 5 of their CD's and I doubt if I like much more than the odd track per album but I'm glad I've heard them even though they haven't widen my tastes but rather signaled the end of the line on a particular adventure.....................