I'd say everything is not a sign, because you cannot generalize intelligence and probably not truly measure it either. But I think that this doesn't even matter because:

If you get a stroke (or long covid) and you can't finish that IQ test that you previously scored 150 on, are you now less intelligent? Even simpler: are you likely to be measured as intelligent as before while you're going through a nasty divorce or mourning the loss of a relative?

This is why, from where I'm sitting, while of course having developed cognitive skills like problem solving ability make a huge difference, attitude is much more important in life, and often a much more critical success factor than (perceived) intelligence.