Actually, nothing.
I started in my mid 30s with woodworking again after only having tinkered a lot with wood as a child. I don’t have any regrets, it’s a fantastic hobby. V1 was the final push that I needed as a computer enthusiast: It’s woodoworking, it’s computer, it’s fascinating. I had always wanted a printer as well so it all came together well. You can still see my beginnings in the Schneewittchen thread. 
The only thing I should have done earlier is to register a business for 3D printing, that’s pretty easy money with (often) minimal effort.