I think the old adage "Girls mature faster than boys" comes into play here.Commitment is a sign of maturity, and it just takes some of us longer. I know if a girl seems unsure of herself in bed, it gets distracting and starts to feel awkward.Commitment means I've found my soul mate, that I am completely secure with myself, and that there should be no going back.
I don't feel pressure in that sense, but I do fear that my appearance and my "game" (not that either are working for me presently) will fade as I get older.
But if the baggage becomes apparent too early in the relationship, then a guy will probably bail.
Also, baggage causes people to put pressure on or damage a relationship, so it may be doomed from the outset. Commitment means that I've decided that the woman I'm settling down with is perfect and there is no one else out there for me.
But I've learned not to make things worse by suggesting that she's PMSing. If a guy feels like he does not deserve a woman or is not good enough for her, he will become jealous easily and worried that he's going to lose her to another guy.
On the other hand, I admit that I have tried to make girls I'm interested in jealous on purpose before.