I think that idiom or expression in its original form should be "Don't trouble trouble till trouble troubles you". (1st trouble is a verb, 2nd a noun, 3rd a noun again and the last one a verb) It simply means "Don't go looking for trouble or problems - let them come to you".

Well, that sentence doesn't make any sense at all. If you want to learn English I would recommend www.eslcafe.com/. Good luck Charles! P.s. It should be "Who knows what this sentence means?"