Just finished my second day in an 'open layout' office of 20 somethings as a front-end lead (react/redux) after working remotely from home with a small team of 'seasoned' pros for the last couple of years.
I'm sure there were some raised eyebrows when I showed up but that seems to have passed now mostly because they see I know what I'm doing. I've had a few moments of reflection wondering what the hell am I doing here but I love software development and made a conscious choice not to take the management route.
Had my first of 2 kids @ 40 and find when I start slipping into a regrets of what I haven't accomplished I see them and am reminded of my real purpose these days.
I still feel young on the inside but sometimes look in the mirror and have to acknowledge I'm not 20 something anymore and that's a bummer. But I was walking to work this morning pondering all of this and walked passed someone sleeping on the street and checked myself.
I remember the first time I saw Doug Crockford and had a profound realization that you don't have to outgrow programming. Seems silly now but not at the time.
My dad is 77 and can still kick my ass on a squash court so I try to focus on what is still possible instead of reflecting on what I haven't done.