While I agree with your sentiment, let me add my own personal clarification. Grow up to the point where you know how to behave in situations that might require you grow up(ie, financial, professional, emotional) but always have the heart of a child and have fun in life. Don't have too many regrets no matter how insignificant something may seem in the grand scheme of things, if you geek out over it, geek out til you can't geek out no more. Life is way too short to not have fun, but it's also long enough that you do need to adult a few times in your life