Re: Confession of sins from years past..
The part of your Confession where you say "I'm sorry for these sins" (The one's just confessed) and then you say "and the sins in my past that I cannot remember" Covers them.
Many today think if I didn't know it was a sin then I didn't sin! Wrong!
If the action or thought, was sinful then you sinned. The guilt may not be held against you because of your lack of knowledge or the circumstances. When you discover that it was sinful however you should confess it.