不自量力
Go beyond one's depth.
Overreach oneself.
Bite off more than one can chew.
Throw straws against the wind.
eg:Trying to solve that problem is to 90 beyond her depth for Lily.
中英俚语俗语来源:战国策·齐策三:“荆甚固,而薛亦不量其力。”
同义词:瞠臂当车 Kick against the pricks.
反义词:人贵有自知之明 Know myself.