I've never had lessons, but I can play beacause I can read music, so I incorporated that into the piano. However, my skills are limited. To be really good, do I need lessons or could I just use piano books that teach you.
I am a piano teacher but I would say you can teach yourself to a certain standard. As long as you keep trying and practise. Give yourself goals, pieces you want to play etc. If you get stuck you can always have lessons once a month etc, just to keep you going!
Good Luck!