The Eternal Fool's Philosophy: Asley's Principle

The Eternal Fool's Philosophy: Asley's Principle
When he was young, he failed at the Magic Academy and was ridiculed by his classmates.
In order to get revenge on the people who made fun of him, he began researching magic and magical artifacts outside of the academy. However, by chance he discovered a mythological medicine, and with it he obtained an immortal body.
Before he realized it, 5000 years of research had passed and he had become an ancient magic user.
And thus, the people he was seeking revenge against were long gone. Losing his purpose in life, Asley went on a journey with his familiar, Pochi, to see how the world had changed after 5000 years.
After an unexpected turn of events helping many humans, he is now living at the magic academy.
Asley. A 5000 year old ancient magician who looks like a young man. How will he live his second life’s youth?