Well, to put it simply, I traded my life for a girlfriend.
Oh, in that case, there are basically three explanations.
For example, his girlfriend has an incurable disease, and he wants to exchange everything he has for his girlfriend's health.
The other is being dumped, and he is willing to exchange everything for his girlfriend's change of heart.
The last one is that his girlfriend really went, so he used this emotional sentence.
I guess I've seen too much steel refining, and I think everything can be exchanged equally-