My baby (#3) is 17yo and I do get nostalgic about when I had three little ones who were excited because I said we'd go to the park and take a picnic.
But as they get older, you can get excited (and sometimes scared) about what they are learning and becoming. Mine are 24, 21 and 17, and the two younger are picking their own way through life with things I'd never have dreamt of at 9yo.
And you can enjoy that they are a little bit independent, can be left to do their own things while you do yours, and have their own opinions and ideas.
Ds still often has me creased up at some of his ideas, which hasn't changed since he was 9yo. Dd2 is still a drama queen (maybe I should have guessed what she'd end up doing) and dd1 has just baked and iced a cake which looks too good to cut. Well, that's what I've just told dh.
So it's fine to look back with joy and sometimes regret (why didn't I tell ds that daily showers were non negotiable when he was still young enough to pick up and put in!) but also look forward while enjoying the present.
9yo is still young enough that they can find pleasure in days out with you. But go for their interest. Dd1 likes to go to a coffee shop and talk just us. Dd2 prefers a theatre trip. Ds at 9yo would have gone anywhere for a WWII museum/event.
They think they're grown up but aren't really. They need your input still.