My mom and grandmother love to study. There are some super cheap courses that they attend. Some are special for older folks, others are open for anyone and some are even official part of university courses (my mom and grandma can attend as "listeners" because they are not unrolled in the university, it means they dont get a grade, or a certificate, but can attend classes normally).
They have studied so far many languages, foreign cultures, astronomy, geology and much more! These courses are offered by a public university, private knowledge schools and embassies. Check out if theres something like that around. If he's interested he may apply, make friends, have homework to do, places to go..