Brought to completeness of growth and development: well, physically, I guess I'm mature. There are still changes (joints wear out, pounds shift from muscles to fat, hairlines recede), but for the most part, I yam what I yam, an' that's all what I yam. But the mental side is something completely different. I'm still learning new things (being in the business I am, if I quit that, I'd be unemployed in a hurry) and still trying to figure out some of life's big questions. But the whole discipline of philosophy is people trying to figure out life's big questions, so I'd like to think I'm in pretty good company there. Overall, mature, according to this definition sounds to me like it means "dead", and I think it's a good think to avoid deaditude.
Fitted by growth and development for any function, action, or state, appropriate to its kind: I like to think I'm pretty well fitted to my life, but there's lots of evidence I have plenty I still need to learn. I'm still a single guy, I still don't own my own home, and I have many of the traits my parents were thinking of when they used the word bachelor as a pejorative. I remember my dad telling me once about the bachelor who lived up the road from them when he was a kid. The guy was in his mid-thirties, apparently hadn't really settled into any one job, drank, and generally just wasn't acting like a grownup was supposed to at the time (the 1930s). That all sounds pretty familiar to me. I guess it's a good thing I don't live