Otter's Rock

The randomness of which preposition languages pick is just nasty in general, and it's really frustrating that sometimes they correspond across languages and sometimes they don't. Like why are we sitting in front of the TV but behind a book? And how about a computer or a monitor? Like in German you sit in front of a computer but in Russian you sit behind a computer when you work on it, and in English I've seen both. It's really arbitrary.