Since Alfred has the body of a 19 year old, every couple of years he'll attend high school or college for a semester.

He attends to make sure he's keeping his knowledge up and because he loves to be in a place where it's OK to act like the teenager he is for once.

P.S.

He loves to troll the World History classes.

"I'll admit it... I have a 158% in World History..." He grinned.
                  《☆》《☆》《☆》

Who doesn't love to troll the world history class. XD I live this headcanon it's completely adorable and realistic.