From Longman Dictionary of Contemporary Englishget above yourselfget above yourselfPROUDto think you are better or more important than you really are → above
Examples from the Corpus
get above yourself• Ever since he'd given her that power of attorney she'd been getting above herself.• What was Cambridge, after all, but a small town which had got above itself?• I was thought to be getting above myself because I refused to sight read a scene. 