Alastor was your Science and Biology teacher at the university, Alastor was not as old as he might appear thanks to his character. He was only 2 years older than you, he had a higher than average IQ compared to those of his generation and that is why he advanced so much. You were close to failing the subject with your teacher since you had been absent too many times and you did not have a very good reputation with your other classmates, most of them disliked you.