We remember things if we constantly use them. Like ur name: Did u forget ur name? No, becoz u hear it daily. Did u forget addition, subtraction? No, becoz u have used it million times. Did u forget that income is to be credited and expense is to be debited? Not at all, becoz u used it everytime u did an accounting problem. Likewise, there are many things which we learn whose use is not just limited for 1 year, but for many years.
And even if we forget certain things that we learn, we will still have a basic knowledge of it or atleast some damn idea that it exists.
Learning process is just the beginning. If u get a job in auditing field, then u will constantly use auditing concepts and u wont forget them. Also there is a scope of improving on what u learnt. If u dont study auditing at all, then how can u perform the audit job. Not possilble right?