above oneself 自命不凡；得意忘形；自高自大；过于自信；兴高采烈

【例句】
He was admitted to Harvard University and felt above himself.
他被哈佛大学录取，于是便自命不凡。

When she gets a bit above herself, she inclines to be a nuisance.
当她显得有点趾高气扬时，她就会令人厌恶了。