What's worse is that this same person will have 100 reasons why they couldn't do a damn thing for your birthday - "you're hard to buy for" is the convenient blame shift - and, of course, a restatement of the extremely important task they (and only they) had to do that prevented them from even thinking about your obviously insignificant birthday.

Take this person out for an amazing dinner on a Friday night and a show and .... a walk by the river and give them a gift - all in celebration of their birthday, but then fail to give them the proper gift the next day (their actual birthday) - HUGE fight and they are looking for a new place to live. Nevermind that they specifically requested the Friday night out so they could rest on Saturday - YOU failed to realize they needed even MORE attention.