Why do you automatically assume that not being able to complete the tasks you assign for yourself is a medical issue? Maybe "boys being boys" (and sometimes girls) just means they are not well suited for the kind of tasks that they are supposed to do. They might still be perfectly suited for other tasks.

So if Ritalin helps people to achieve their goals, great, but I don't think it implies that they had a medical issue when they were unable to complete those tasks.