I've only got myself as a single data point, but I'm 100% sure that in my early 20s I could interview much better than I do today when it comes to on-the-spot i

I've only got myself as a single data point, but I'm 100% sure that in my early 20s I could interview much better than I do today when it comes to on-the-spot interview questions like implementing tree insert/walking algorithms, reverse this structure in the least steps possible, etc. Yet as a 38 year old I write far better real-world code today than I ever have.