Why does a guy dump you after one day?

well if i guy dumps you after a day it means they dont really care about you and they're not really taking it seriously. if they're young like 12-15 and they see a pretty girl, they'll want to go out with them but not really care so much about them. that's why it's good to know a boy properly before you go out with them. or even better wait till your a bit older than 14 before getting a proper boyfriend :)