Thanks for sharing, that is very interesting. The article quoted several of the studies as saying that the benefits of creatine are mostly on "stressed" population. Maybe that's what's going on here?

It might have some kind of neuroprotective effect. For people who are already very healthy, there may be no measurable difference. But for the rest of us, it may be more helpful.

I'm reminded of something I read about dual n-back. (I forget where, it might have been Gwern page on it.) Someone said that when they are sleep deprived, they feel totally fine, but their n-back score absolutely tanks.

It might be interesting to test that, the intersection of sleep deprivation, creatine and objective measures of executive function. That could give us more data on the "helps most in stressed cases" theory.