Most Helpful Guy
You never want to get rid of your diaries. Sometimes you can look back and observe your thought processes and realize 10-20 years later, you haven't changed that person inside. It gives you precedence in case you find yourself in a tough emotional situation and have to make decisions (since you already know the outcome having been so long removed from it).
I never kept a physical diary but I did often log some "late night" thoughts onto text documents to help develop meaningful lyrics. These entries were a thorough dissection of my psyche, and my mind had not changed at all. 6 years later I was still self-loathing and felt inferior. That's when I learned to be more endearing of the moment, even against my will, because stone walling everything in order to feel safe and assured does not lead to the happiness I want.
If you're afraid of hurting some people, that's what makes it EVEN MORE valuable because guess what? It can prevent you from doing the same thing to someone who really means a lot to you.