lose your marbles含义不是指“丢了你的弹珠”，其正确的含义是神智不清，失去理智；脑子出问题。

【例句】
I'll tell it to you, although you'll probably think I've lost my marbles.
我会告诉你，尽管你可能觉得我已经失去理智了。

My poor grandmother started losing her marbles after she had a stroke.
我可怜的奶奶在中风之后神智不清了。