get above yourself
US /ɡet əˈbʌv jʊərˈself/
UK /ɡet əˈbʌv jʊərˈself/
1.
to think that you are better or more important than you really are
:
•
After his promotion, he started to get above himself, treating his old colleagues poorly.
•
Don't get above yourself just because you won one game.