Nothing you put up on Facebook goes away on its own. Your profile probably has photos and status updates in it from years ago that you don't even remember posting.
Unfortunately, some of these posts might be things that you wouldn't post today. Maybe you posted them with the wrong privacy settings and everyone can see them.
Either way, taking some time to look at and clean up your Facebook history is never a bad thing. Otherwise, old posts can come back to bite you in a job search, relationship, legal case or phishing scam.
Fortunately, Facebook makes it easy to review and clean up old posts.