Diversity of learning languages

As far as I can remember, I've learnt French in comics when I was five.
I've learnt English on the web when I was 13.
I've learnt Romanian at work when I was 25.
German is the only language that I really learnt at school, from 10 to 18.
(Apart from Ancient Greek, a pleasure I had when I was 13-14.)

Why is that?

One argument may be that I've had very good German teachers all along my school time, whereas I've had few good English teachers, especially in earlier classes.
Maybe I could say German is a more school-oriented language. Simpler and more logical than many other languages.
Maybe German is the most distant from French, in terms of vocabulary, making it easier for me to master it with regular work.
Maybe that's just me...