I haven't had any mentors so far. When I started my work life in Italy I immediately ended up being tricked and not paid for a job I had done. At the same time I had a few other important failures in life that taught me some important lessons.
The most important one is to have a clear goal in mind and to continue to go at it and have a strategy that you continuously put to test and change. There will be many failures and that's alright.
A lot of times you don't really know something until you've tried it on your skin, especially in life.