(someone) thinks (they) are so smart(redirected from he thinks he's so smart)
(someone) thinks (they) are so smart
Someone is not nearly as intelligent or witty as they believe or would like others to think. You think you're so smart, with your fancy degrees and six-figure salary, but you wouldn't know the first thing about how to survive out in this part of the world. Sarah thinks she's so smart, but she'll be in for a rude awakening when she starts college at Harvard next month.