Get over yourself
Definition 1 of 1
Pro Tip 1/3Situational Use
Use it when someone is acting too proud or self-important, suggesting they be more humble. 
He kept bragging about his new car – I told him to get over himself.
Pro Tip 2/3Casual Tone
This phrase is informal and best used in casual conversations or with friends, not in formal settings. 
I can't believe she said that at the meeting. She needs to get over herself.
Pro Tip 3/3Not Literally
It's not about physically getting over something; it's a metaphor for changing one's attitude. 
Stop whining about your minor mistake – get over yourself and move on.