I expect you are right, I think he was an undergrad when he started it. The difference between Linus and Tannenbaum is that Linus was eager to see linux develop into something interesting. (thats not to say, a major operating system, just more like something interesting.)
Tannenbaum, in an interview I read about a year back, said Minix was never intended to be anything other than a teaching tool so he resisted all attempts to add functionality to it that would make it a "real" OS. Which is also why Linus Torvalds decided to write his own.. I think he wanted a terminal program or something to work on it.
Tannenbaum said, if I remember correctly, he doesn't regret one bit that his student has become so famous, his love is being an educator, so you are happy when your students get it. Have to look that interview up, it happened because of the SCO trial and some shill trying to "prove" that linux was stolen. Tannenbaum isn't big on interviews either, at least that was my recollection. It may not have been an interview, but an open letter. I must be getting old.
I found it! "Who wrote Linux" by Andrew Tannenbaum. This guy is a hero even if he is a bit of a flaming democrat.
I hadn't read that before. Sounds to me like Minix was a success in exactly the way that Tannenbaum intended! What more could one ask for?