Justification

Why is it that I feel I must justify everything I do? I added a journal functionality to GITI, and I question myself as to the usefulness of it in the future. I find that I like going back and exploring my past sometimes, shouldn’t that be justification enough? Other times I feel pressure from people outside myself that want justification for why I do things, such as why I have a blog, or why I do or dont want to certain things. Is it not enough for me to just have an opinion?