I cannot believe that the purpose of life is to be happy. I think the purpose of life is to be useful, to be responsible, to be compassionate. It is, above all to matter, to count, to stand for something, to have made some difference that you lived at all.
One of my favorite tricks was taking a page and having the first student translate it from English into whatever language he or she was working on, and the next one would translate it back into English and then into the foreign language, and we'd go around the room and compare the two English versions at the end, and it would be amazing how much survived.