「回到起点」英文怎么说？

（be back to）square one 回到起点，从头开始

Okay ! Let's go back to square one and try again. 

好吧 ! 我们从头开始，再试一次。

I've had to relearn the game from square one. 

我只好从头开始，从学这个游戏了 ！