We must always remember what we acting for

I'll be back . I've heard this phrase a million times. but I can't remember what movie I heard it in. Yet I will continue to hear this phrase. May be I will even say it. I don't care much about etymology. So I'm not even interested in the meaning the word originally had. The most important thing is whether you are communicating with the other party. The purpose of language is to accurately exchange information with others. And to cooperate with others. We must always remember what we acting for.