Yep, energy drain can still sneak up on you for a while yet. At your stage of recovery, most days you will be fine with energy. But for no discernible reason —maybe a new activity, maybe a bit more activity than usual, maybe something you never figure out— you will be laid out by the energy drain and need a nap. It isn’t a symptom of old age or anything. It’s just that the energy drain is still stirring under the surface. At some point you’ll realize you haven’t felt it in a long time and realize it, too, is history.