Travel and literature aren't the only good reasons to learn a second language. A second language is also another window into word origins and sometimes another window into your own language, if they are related!
Somehow the use of the same word in Contactlinsen (contact lenses) and Linsensuppe (lentil soup) completely escaped my notice until Damon said something the other day when we were walking past an optometrist's office. We then wondered if the words came from the same origin or if they had converged from separate origins. A quick web search later: They come from the same root! The Latin lenticula, from lens, meaning 'lentil'. Lens is also the genus name for the lentil plant. Lenses are so named because they are the same shape as lentils.
Language is cool.