There are so many things in English that make no sense when you stop to think about it.. it must be really hard to grasp for people not born into it. I saw a list somewhere of all the words with double or triple meaning and it's crazy! We never even think about it since it's 2nd nature.
Yeah, it's crazy. I would imagine that a lot of them come from words brought over from other languages. I'm sure by this time that the 400 year Brit/American English world dominance has led to a ton of English words being melded into other languages. I know it's true with (South American) Spanish. And I'm sure there will be a number of Mandarin words entering world languages in the not so distant future as well.