Think more stuff like "find the angle of lines defined by (x-4y-1=0) and (x-y-2=0)", "write the number 2026 in base 7", "solve an equation sin^2(x) - sin(x) = 0".
I plucked these from our country's high school final exam from this year. Back when I was in high school, I did mine in 60 minutes without an error when the time limit is 150 minutes and I intuitively immediately knew how to approach each task since the moment I saw it. Also all needed formulas are supplied, you don't need to remember any of them.
I plucked these because for these I don't have the immediate "know how" now, I still understand the topics, and could solve them with enough time, but it would require some thinking and thus I would be slower at solving them than when I was in high school, even though I'm pretty sure I could still ace it in the 150 minute time limit.
But reality goes beyond high schoool... College-level math, like derivations/integrations, sums, algebraic proofs, is even harder and solving some of them could take me hours when I could do them in minutes when I was in college.
With code it's the same. I could solve simple Python/Pascal/C++ high school level tasks as fast or faster than when I was in high school, even if I didn't write any code for a couple of years. But we also had assembly class in college, and I would struggle at assembly if I had to code it now, 10+ years later, even though I didn't struggle with it back then.