The Urban dictionary has 78 definitions of Cougar:
http://www.urbandictionary.com/define.php?term=cougar
It has 3 for Dirty Old Man:
http://www.urbandictionary.com/define.php?term=dirty+old+man
Gotta love the descriptions and comparisons of each description.
Personally, anything over 15-18 years for me is too much. It starts to get into the *could be a parent, albeit young parent, range*. Different music, different movies, different clothing, etc.
And yes, it is entirely possible to enjoy all those things from different generations. Enjoying things you don't like is a lot easier when the person whose stuff you don't like and you are trying to appreciate has lots of money to make you forget why you really dislike Mozart or Bach. Or Eminem. Or the BeeGees. Dollar signs and smiles cover up a lot.
BTW, is there a name for men who date much younger women? Since women have recently been labeled Cougars, what is the label for men. My bad on Dirty Old Men. I apologize for that.