the gradation from 'careful' onto 'careless' and then finally 'carefree,'
This is odd, yes. (Belated welcome aBoard.) If you think about it, careful ought to be the opposite of carefree! Full of cares, as opposed to being free of them. Hmm--maybe it's the singular/plural use that makes the difference; full of care (careful) is not the same at all as being full of cares. I feel sure something about this has been discussed here before, but I can't be bothered to look it up (LIU); I've only been here for flying visits this week, anyway.
You will find that threads sometimes (snort) go off-topic, here. Since that happened to a thread I started not too long ago, let me just quote myself; not much relevance in linking to the entire thread:
"I can certainly see where you and other new people might feel a little hesitant to "break in", as it were. That troubles me, but I don't quite know how to make it easier, either. I suppose it could be treated as though you were in a new job; all the others know each other, yet you have every right to be there. Some people may reach out to you, but no one is actually obligated to. You may need to find your own way. Yes, there are some inside jokes; there are pretty well bound to be, in an established group; but you'll learn many of them in time, and become part of others, yourself."
