Which Birthday is the most difficult? [POLL]

Birthday's are suppose to be fun. As a kid, we can't wait for our Birthdays. But as we get older we tend to hope our Birthday comes and goes and nobody notices. I do know a small group of people who take ever Birthday in stride. Not every Birthday is a downer, I have had Birthdays that were amazing. But I think we all fear turning a certain age. For some that age is different than others.