"I think that someone’s fear of a ‘milestone birthday’ directly relates to how happy they are with their life. If you love what you do and are surrounded by good friends and family, then forty or fifty or sixty is just a round number, not a cause for panic." - John Wood
As I itch closer to turning 30 in a few years this part from 'Leaving Microsoft to Change the World' really hit me. He's absolutely right and it makes me want to put even more effort into spending time with friends and family. It will be those times and moments that I will really cherish once I'm old.