It's all well and good to speak of fluidity but one must appreciate the extent and the nature of that fluidity, because both are limited. Saying "messed up" doesn't ignore the fluidity, it just makes a statement that is relevant to the situation now. There would have been a time when it was not, but that time is not now. You're welcome to make arguments about why it ought not to be the case, but that would require delving back into insightful statements and not quibbling over semantics.
Anyway, to answer Strop's previous, likely rhetorical question leveled at me, it probably makes you a bad person.
Allow me to play Devil's advocate by posing a counter-example (Nicho may have some comment on this): I have a socially conservative, very traditional Christian Singaporean colleague who specifically wanted to go out (and marry) a girl whose primary quality was innocence and vulnerability, specifically so he could be, essentially, her knight in shining armour. He was very earnest about this, too, as he firmly believed that he had a duty to "be the man" just as the woman had a duty to "be the damsel in distress" (now I'm being facetious).
Naturally my female friends did not understand this and thought it was pretty darn creepy. I, myself, have very different tastes and like girls who are independent and capable. But I did not think him a bad person for feeling the way he did.
As for the topic of cougars... interestingly my medical registrar counterpart asked me what I thought the actual
definition was, given lack of consensus, and I arrived at the conclusion that there were trends as to the age group and demographic of involved parties: the women were often referred to as being at least in their 30s and older, and the men late teens to early 20s. Why was that?
I figured the first part had at least a precursor in
Sex and the City, in which the single women protagonists were all identified as having reached "the big three oh". As a decade milestone the (perception of) expectation is still on women to have already made serious moves towards settling down with mister right (if not already done so) and having kids (if not already done so), a serious shift from the modern values of the affluent early 20s which are deemed "way too early to have kids". There's a conflict in there somewhere, like opposing pressures squeezing an individual who straddles this age.
As for the men, there's an increasing phenomenon called the late 20s crisis. A young man often seems to go out and graduate and then work and party with wild abandon and no thought... this directionless flailing seems to catch up to them not in the 40s anymore, but the 20s, wherein they go seeking some kind of enlightenment by travelling or doing some new agey thing or whatever. It's this wild abandon that characterises the "boy toy", since men are also, to an extent, also expected to "mature and settle down".
At least that's my take on the matter.