There have been some interesting studies about how prime athletes decline. There is often an assumption that someone is "too old" to be a top player anymore, when the reality is usually something psychological. Basically, younger players tend to have less distractions in their lives and be "hungrier" to prove themselves.
Older athletes rarely maintain the single minded focus necessary to stay on top. Sad, but humans get bored of things and want to move on. If Paul's career ends up petering out disappointingly, it might be because he's too rich and too comfortable to keep pushing like he would need to. If that happens, no question Climo will have had the more impressive career.
link the studies