What is it supposed to do? Unlearn driving style? Ours seem to react to the conditions of the immediately preceding few minutes, ie if one has been ambling along, they short shift, if ragging it, then they change up later and down earlier. Just an impression with no hard fact to back it up.
I reset my gearbox and throttle body adaptions every few months. Basically a hard reset which resets all the various "learnt" values. I find that as I do a lot of motorway miles the gearbox gets lazy and the change points become longer, a reset back to the default makes it a bit more sporty feeling so I just do this when I remember. It's certainly not an urban myth on my car, a placebo maybe but not a myth