People blow on hot food to make it a temperature better suited to their mouths. My teeth are sensitive to cold so for a long time I would blow on ice cream before eating it.
A childhood belief about general

others believed things like this
- I used to think that if you didn't blow your nose and just sniffed the snot up, you head would blow up.Anon
- I used to believe that eating burnt toast would make your teeth whiter and would brush your teeth for you.— Natasha
- I used to believe that if you had to fart and held it in too long that it would cause you to blow upAnon
- My dad told me that when he was little, he thought the trees waved back and forth to make the wind blow.— casey
- I used to believe that when people got shot in the head that their heads would blow up. — Emily
- when i was little i used to beleive that if i coughed, sneezed and farted at the same time i would blow up— fart