To be true to myself and where I am in life.
I was always swayed by peer pressure or even just particular social norms (be married by a certain age, get degree and then job, move out of home by a particular point in your life etc...), I always felt guilty that my life was more free flowing. But the more I lived it, the more I enjoyed it and I realised that I am not a particular type of person.
Now, I have a great job, steady income, an active social life, I have a lot of fun and can mostly do things when they suit me. Since leaving school, I mostly had all of those things but I felt a hesitation to let it go.
It still feels great to this day, I just wish I had learned that in my earlier teens.