Meaning/Usage: Used to tell someone that you made a big mistake

Explanation: When something blows up, it is destroyed. Therefore, blow up implies in this context means to make a big mistake to damage any opportunities. Because making mistakes are very common, a simple way of saying this was needed so people started saying, "I blew it."

"I really thought I was going to get the promotion, but I blew it."
"I thought he really liked me but I blew it."
"I was trying to surprise her for her birthday, but I blew it."

A. "How did your interview go?"
B. "Not so good, I was very nervous."
A. "Why were you nervous?"
B. "I think I might have messed up on a few questions so I think I blew it."

Other Common Sentences

"I messed up."
"I missed my opportunity."