The notion doesn't exist. If one actually "grew", then one would "grow out" of Scientology and "move on".
Scientology keeps people fixated and located in one entrapped tiny little mindset (that pretends to be all and everything).
Change (away from Scientlogy) is not tolerated and is always veiwed as "evil" or "bad".
Involvement with Scientology is, simply, so incredibly stifling.