I have a friend you had a sizable exit from a startup he worked in for a long time. He has formed many academic collaborations, teaches at several universities

I have a friend you had a sizable exit from a startup he worked in for a long time. He has formed many academic collaborations, teaches at several universities and delivers talks at many international conferences. Most of the time paying for his travel and accommodation expenses. His motivation: to share his knowledge and experience with the next generation. An example of paying it forwards.