It's an interesting debate when it comes to politics.

Some 80+-year-olds are sharper and wise than 30-year-olds - and I'd rather have them making decisions based on wisdom rather than 'I want it now'!

If my opinion mattered, it's a subject that can only be determined on a unique scale. That is, if the POTUS - or any person in power - doesn't know the days of the week or who is who, then it's time to call it quits. Stumbling up a step? I do that all the time! It doesn't mean their brain isn't working.