I always answer with an upbeat non commital answer. Usually something like : I in an upright position and am here so this is a very good day. Another: Just took the magic elixer and am getting the groceries before it finishes with me. You have to have a playfulness and a big smile when using these type of replies. My aim is to make people feel comfortable about aproaching me so that I can keep them in my circle. It also boosts my own spirits for a moment to be very upbeat. If I stop and think too hard on how am I all sorts of bad thing will crop into my brain and that isnt good for me now or long term.