no, i do consider myself an adult, sort of, I'm not a kid anyway, though until I find a new job I can't really consider myself a full adult because I'm not economically independent.
I dunno, for me, old are people that are older than my mother (so, born before the 1950's), and people that are fully grown up are about my sisters' ages (so, in their 40's), and someone is "my age" if they are 22-35, and anyone else is "young".
My mother didn't used to be old, but she came to visit me in May, and I helped her up the stairs and helped her to get out of the bath tub, and helped her to walk to the tram stop with me, so she is definitely old now.