I mean, fast track??? 

Not so sure about that descriptor, and if it applies to most of us mere mortals, but the idea of taking a detour or two seemed to be intriguing, nonetheless. 

The consequences of a mid twenty/thirty year old taking time off might not seem to them too fraught with negatives (except for their immediate family members who will be beyond insane about this decision).

It's the "late in their career group" that seem to be exploring this phenomena. 

Is this a trial run for retirement? I suspect so. 

A put your toe into the water maneuver, try alittle of this and alittle of that. Am I altruistic, one wonders? A do gooder in disguise?  Have I forgotten how many children I have, their names and what they do? I'll take the time to reacquaint myself with them. 

Certain, I would think, that this, for the progeny, is not their objective or wish.

The fall back of having your job waiting for you makes this exploration easier. Sort of like living with your honey before you tie the knot. Or, taking a cruise before you move into the over 55 year old retirement community. 

So detour, sabbatical, exploration has become the way to go. As for being a "fast tracker", you could call yourself Sun King. After all, if you are no longer there to defend that you deserved that title, who's to know?