All these years that I had spent in the service of mankind brought me nothing but insults...
 

"All these years that I had spent in the service of mankind brought me nothing but insults and humiliation."

This was Nikola Tesla's last message to his mother.

Just goes to show you.

https://pbs.twimg.com/media/ERLKidbXsAAHNyx.jpg

If you look at his history, his final years looked sad.