Hey, that's an interesting question, BBR.  I'm an old fart on this forum and I can say that it's better for me, even though I voted that age was just a number.  
I have always believed that "age" is a relative thing.  For instance, maturity is not a function of age - I think some seventeen-year-olds are more mature than some forty-year-olds.  Getting older does not necessarily make you wiser or more adult.  As for aging... personally, I'm in better physical condition now at fifty than I was at seventeen. 
Something that makes tickling better with age is my own attitude about it.  I'm a lot less shy about tickling now than I was in my youth.  When I was young, if I witnessed someone tickling someone else I'd blush bright red and haul-ass out of the area for fear that someone would see my interest.  Now I'm more likely to help.