Idioms/vocabulary from the song " Do I wanna know"

Arctic Monkeys- Do I wanna know

idiom. : a powerful and generally secret weapon, advantage, etc., that can be used if it is needed. 
Origin: cheating at cards.

Do you not realise you are emotionally committed.

idiom: crawling back to someone: asking for forgiveness or begging to be taken back by an ex or similar.

You've had some alcohol, generally quite a lot.
Note: British English: a few is an understatement meaning a lot.

I'm constantly about to do something, but probably won't do it because I'm afraid/nervous/not brave.