I just feel like me. How do young and old feel? I have aches and pains but then I have had different aches and pains in the past. I am happy with my 'now'.
same as Tilly. No, I don't feel young in heart, or in body. I'm very creaky, but I am vastly more experienced and knowledgeable and marginally more tolerant. My politics haven't changed either, which I'm told is unusual.
As a pedantic type I hope you good folks mean child like rather than childish. Totally different meaning.
It is a bit like antisocial and unsociable, very different in meaning.