Would you be willing to say what the why turned out to be? Not for us to fix it — the specific ones people land on after a few months tend to be useful to others reading. And if it's something you spotted in your own trade history, we're always interested in what made it visible, since our exports don't surface everything.
Now write it down as one line and read it before you size a position. "I know why" evaporates the second something moves fast, a sentence on paper doesn't. And keep your size small enough that the next relapse costs you a lesson and not the account.