Does Taurus change his mind easily

I started seeing this guy who appeared to be head over heels about me. We had amazing time together. He's very smart and hard-working and recently received a prestigious grant to go teach at the university in another country to go away for almost a year.

When he told me that, I got sad, obviously because he was leaving. He noticed my reaction and asked if I was disappointed because he was leaving. He asked what did I have on my mind: "We'd see each other for a few months until I'm gone and then when I come back, we'll just pick up where we left off?"
He had only 3 or 4 months to get everything ready for the new teaching position and for the professor who would be taking over his place in the states as well. So he was EXTREMELY busy with everything, but made time to see me.

We went out again and he was making plans for the next day to go see a movie and stuff, all attentive, romantic to me. He couldn't take his eyes or hands off of me. But the next day he called and said he decided he didn't want to go on seeing each other anymore. He said he had a lot on his plate and just not at a happy, content place in his life. I was really taken by surprise, because everything he did and said showed how much he liked me.

Anyway, he left. Three months later I'm still thinking about what happened and why he changed his mind. I asked my guy friend for an opinion and he said, the guy either 1) Had someone else or 2) More likely just didn't want to jeopardize the quality of his work and having to think about me so many miles away. He said that some people just cannot compartmentalize things easily.

What do you think? Why did he change his mind like that?

Well, I have to say, I thought there would be no need for me to prove or disprove anything since my question was not about that. His feeling were obvious. But if it helps, I can explain why I thought him being very much into me: we've known each other for several years and dated for several months. He wanted me to become his girlfriend but I wasn't sure. He insisted. He took me to the nicest places and weekend getaway trips, he always planned the next date while we were out and he always remembered my birthday, sending me flowers and making me feel special. Everything I did or said he liked and if he didn't like, he liked that also, because he thought 'differences add some spice.' He would simply say that I made him happy just because I was Me. That's why I think he had strong feelings about me 🙂