Definition: In this task, you are given a Reddit post as a text. Your task is to generate a title for this text. The title should start with "TIFU by", followed by a situation that caused humor. The title should contain 7-12 words, ideally.
Input: Text: so there i am, an 18 year old bagging at safeway when a cheery woman between 50-60 comes through my line. she nudges the pop-out handicap check writing platform and says "i bet no one uses these anymore!" and goes on about how she never writes checks anymore. now i'm 18 but i could pass for 12 so i joke about my young age and say "i've only ever heard about those times!"  the woman's smile slides right off her face and i realize she thought i was making fun of her being old. she finishes the purchase without saying another word i try to give her a cheerful "have a nice day!" so as to communicate i wasn't making fun of her. she makes eye contact with me and i can tell that she's going to think about her age for the rest of the day. the look in her eyes told me i had ruined her.

TIFU by joking about my age to a customer