I don't know if I've ever had a mentor, at least not on a professional basis, and certainly not anyone that I wasn't related to or friends with. I've learned from different people over the years, but I don't think there's one single individual who stands out over any other.
I've been somewhat of a figure it out, independent kind of a guy. I try to learn from the successes and failures of others, and try to duplicate the good and avoid repeating the bad. Sometime it works, other times, it doesn't, but it's left me to pretty much forge ahead on my own.
I don't know if I would wish that kind of process on anyone else, especially if they want advice. At this point in my life I'm more willing to be mentored than I was when I was younger, but now I have most of the experience I would need to be a mentor myself, so there you go. :)