I was lucky enough to go to a private school where Latin/Logic/Rhetoric/Greek were taught as core subjects and I've also found Latin incredibly helpful in my li

I was lucky enough to go to a private school where Latin/Logic/Rhetoric/Greek were taught as core subjects and I've also found Latin incredibly helpful in my life. I found learning French and Spanish to be quite easy and reading medical documentation comes fairly intuitively. For those of European descent (at least a large chunk of what we call Europe today), Latin is an incredibly important part of our culture and history and helps link us with an incredibly rich past. I would say for pleasure and knowledge, study any language that saw such developments in medical practice, art and naval/military sciences. I'd assume that Sino-Tibetan language groups have a similarly rich history and learning one of those languages would be of equal benefit.