You'll never really grow up
I was speaking with a friend in his early 50s the other morning and, referring to a change in career that was looming, he said "I'm still not sure what I'm going to be when I grow up."
At Tobias & Tobias we've been doing some research for one of our clients on 'being a grown up.' One of the surprising insights is that being an adult is a journey, not a destination. Regardless of age, many people never feel like they're an 'adult' per se. There are a number of markers of adulthood - steps along the journey - from the first independent holiday (having to cook, clean, and budget for yourself), through going to the doctor for the first time by yourself, right through to having kids, paying off a house, or even thinking about retirement.
As a father, it seems to me that being a grown up is about confidently knowing the answers to things. Understanding how life works and how to navigate it. It's a child's perception of the confidence adults express around them - not the reality. Because, as a 43 year old with a house and couple of businesses, I still seem to see the world like when I was 20-something - fumbling my way through life, waiting to finally feel like a grown up.