"I was one hundred and three last week. But people tell me I look young for my age."
Lol! That's close to mine--"I'm 138. (pause a beat) And a half." Or, "I'm 138, but I have most of my own teeth!" Occasionally, I go with, "As part of the Witness Protection Program, I'm not allowed to divulge any personal information. Oops! I've said too much." followed by a very obvious conversational redirect. All of the above are said with a smile. In actuality, I don't care if anyone knows my age, it's someone asking a personal question that I find annoying. And this topic has gotten me thinking--my next response might be, "You know, no one's asked me that question for a long time. Not since I was answering it with, "I'm *this* (holding up random number of fingers) many years old!"