"How many straight lines are in this surface?"

Me: "Define straight"

@sophieschmieg: [waves hands] "straight! Here, how many lines on this surface?"

Me: "infinitely many"

@sophieschmieg: "exactly, but on this one?"

Me: 🤨🫤 "... also infinitely many"

@sophieschmieg: "what!?"

Me: "well it has an atlas of locally open sets that map onto an open disc, so…"

@sophieschmieg, exasperated: "oh my god, TOPOLOGISTS"

me: 🤷🏼‍♀️🤷🏼‍♀️🤷🏼‍♀️