go to someone's head
US /ɡoʊ tə ˈsʌm.wʌnz hɛd/
UK /ɡoʊ tə ˈsʌm.wʌnz hɛd/

1.
得意になる, うぬぼれる
if success or praise goes to someone's head, it makes them feel more important than they really are
:
•
Don't let that small victory go to your head.
その小さな勝利を得意がらせるな。
•
After winning the award, his ego really started to go to his head.
賞を獲得した後、彼の自尊心は本当に得意がらせた。