失去理智：变得疯狂或疯狂。
... lose the plot 傻了 lose your mind 疯了 lose sleep over sth 担心某事 ...
发疯，发狂
Don't lose your mind.
不要失去理智。
You lose your mind, sleep, becomes anxious for everything.
乱了头绪，失眠，为每件事焦虑。
So what will really boost your brainpower, and what will make you lose your mind?
那么什么东西能提升你的脑力，什么东西又会让你失去智慧呢？
"You could lose your mind in there, " Shargel argued.
Without sleep, you will literally lose your mind.
FORBES: Sleepless In The Big City: Why Leaders Are So Tired (and what can they do about it)
If this small sum of money is unimportant (no money is really 'unimportant' these days but I mean that you reckon you could afford to lose it without compromising your standard of living) to you and you don't mind if you lose it or not then the Stock Market might be the place for you.