@Wondrring I hope you don't mind me chiming in age 50
I was fine at 40. Everything was on track and on plan.
Lockdown ruined everything - also being blunt, with parental health issues in the past, I was not expecting to have an elderly parent in the mix age 50 and I lost a chunk of my 40s trying to look after my mum.
Please do not make the same mistake! No will give you back chunks of your life that you missed - it hasn't helped that the outside world is unrecognisable now, I will never again assume that certain things are still out there to be done and to be enjoyed. Stupid me.
You've not been specific, but I can't help wondering, when anybody asks this question, I wonder if it's a you thing or if it's an environment thing
I haven't got anything massive to complain about
However, I do have this constant sense of "when will things go back to normal?" And it's really hard to process that they probably won't. I've discovered a lot of people are feeling like this.
I think, if you are deeply busy in your family, it's not the sort of thing that affects you. For those of us who aren't, and who are very much involved with the world outside our front doors, it's a very strong feeling. In real life, I've had people in my 30s say this to me as well. It isn't just a "looking back on a golden age" thing.
Also, whenever anybody talks about their future career plans, I have to keep quiet because that's the polite thing to do but I always wonder if they have thought about AI in that context. Whether it's coming faster or slower than you expected probably depends on many things - it's actually coming on slower than I expected in 2016 so that's a relief - but many people weren't in a position to know it was coming in 2016.
In short, there are many reasons you might be feeling unnerved, and I wouldn't automatically attribute them to your age
I used to have periods of uncertainty for no reason. It's about learning to navigate them I think. Though at the moment I have no control over the things causing me uncertainty. But a lot of life is going to be like that, I suppose
Probably not the answer you wanted, but the most honest one I can give you. Please don't automatically look at yourself and think that you're lacking in some way.