i feel the same way about all those occasions, too, really.

but in this case "obligation" especially means "Buy me the perfect gift so that I can SAY you love me more than ANY of the other girls' boyfriends/husbands love THEM," and "You'd better **&^% remember Valentine's Day or you're NOT going to be GETTING ANY for the foreseeable future," and other mindsets that make women seem like assholes.