I love this post from Adrian about what he's learnt from his time as a developer and where he sees himself going next.
Take conscious decisions in your life. Be aware of your actions and their effect. Do not blush or be embarrased for changing your opinions. Say “I’m sorry” when required. Listen. Do not be a hotshot. Have integrity and self-respect.
— Being a Developer After 40 by Adrian Kosmaczewski
The big four-o for me is just around the corner. I can't freelance for another twenty years, or can I?