In my case, I'm certain that I've spent a fair amount of time sliding between growth and reevaluation/retardation. As you would imagine, both goals feel "normal" to me. I suspect we would all say that about our goals; they are what is familiar to us, regardless of how uncommon they may be.
For me, it's easiest to understand and validate the influence of reevaluation by contrasting it with growth; they've been effective compliments to each other over the course of my life thus far. A pattern that I recognize is one in which I slide to growth when I have a need for expansion: to meet new people, take on new challenges, acquire new skills. When I've reached a certain point where the specific need was fulfilled, I slide back to reevaluation to process what was accomplished and the lessons learned along the way. I've been fortunate to be able to accomplish a great deal in this manner - I don't think anyone would look at my life to this point and say "here's someone taking a breather this life." Despite my various outward accomplishments, the happiest periods for me have been those in which my daily routine was simply and singularly focused. However, with my 3rd level impulse towards "being a jack of all trades master of none" (I have a seemingly limitless list of internal and external goals I've set for myself), and having a sage's multiple inputs, I often find it difficult to maintain my focus and keep things simple. I can understand why one might choose a physically compromised body in conjunction with reevaluation in order to remove some potential distractions, although I can also see how doing so could give rise to a different set of distractions related to the nature of the "handicap."
When reevaluation is in full effect, it involves a seemingly endless processing and reprocessing before, during and after the majority of choices I make. I mentally navigate down each potential path and construct as complete a choice/outcome tree as is logically feasible given my assessment of the current possibilities. As many of us are, I'm keenly aware that any direction I choose could represent the extinguishing of many other possibilities; for me, that awareness can be quite inhibiting at times. I constantly return to and "reevaluate" my previous choices and assessments later in life in light of new insights as they are gained. In some respects, being in reevaluation might be likened to being in the 5th internal monad all the time - I think everyone has periods of introspection and reflection in their lives; for me it's basically a constant.
When in growth, choices seem to flow much more easily and freely for me. I still engage in a standard amount of processing to be sure, but I tend to value decisiveness over analysis. I don't feel the same urgency to evaluate every alternative that lays before me or revisit past choices. Growth feels a lot like confidence, like an assurance that no matter what may result, I can not only handle it, but it will augment me in some fashion. (The old adage "whatever doesn't kill you makes you stronger" is more my attitude while in growth). It can feel quite liberating. It's probably clear by now that I'm not 100% "happy" about being in reevaluation. It's a bit like being in detention for acting up when you'd rather be outside playing and getting into more trouble. But I'm coming to terms with it, learning to accept it, and I acknowledge its usefulness.
Michael had this to say to me on the matter:
"This Fragment chose Retardation as the Goal for this life in large part because in the immediately previous life, the Fragment, a major politician in an African state, went in for elaborate and conspicuous displays that led to his downfall. Simplification seemed a more useful impulse for this life, and so does an aversion to many aspects of politics."
So it seems like reevaluation was chosen to help me "take it down a notch" and motivate to reflect on why simplification might be needed and desirable given my particular history. I'm sure there's plenty more waiting for me to uncover - all in due time.
I can obviously only speak to my experience of the goal, but I assure you it's not just endless isolation and reflection!