have a leg up 可不是“抬起一条腿”，真实含义是有优势，占上风。

【例句】
If you've got experiences， you would have a leg up.
如果你有经验的话你就会有优势。

I just hate that this guy has a leg up on us, you know?
你知道嘛，我就是很讨厌我们被这家伙牵着鼻子走。