One up on me

Ashwin was trying to pump the animal balloons with the balloon pump by himself. He would hold the pump up with the balloon dangling down and when he tries to pump air, the balloon would take off. He asked me why the balloon went "buchkoo" (and not for the first time) when he held the pump this way. If he held the pump facing down he was able to inflate the balloon..

I was tired of giving answers so carelessly I replied that the balloon was down and he was trying to pump air upwards and so the air and balloon were fighting against each other and the balloon got ejected from the pump to make way for the air.

"Naan adhu dhaan nenechen", he replied. (That's what I thought)