rar pw

well yes,I admit, I don't know a shit about programming
and, worst of all, i have a problem
everyone of you knows the famous rar files
and that you can put a password on it
now, i lost a password so i can't enter the file
how can i find this password?

This may come across as naive but, if the password is encrypted in the file, shouldn't there be a common or flagged entry point for accessing it?