Wallstein;
That feeling is what many are looking for. I've noticed, for me recently, it's been harder to find. Being harder to find, it negatively impacts my motivation to chase it. It's a viscious circle. For the first time, I'm struggling with summoning the drive, the desire, the hunger, that used to propel me to push myself, seek the edge, and enter that zone that you describe. The mountains will always be there, the routes will stay on my list, I'll climb them when I'm ready. Until then, I'll keep looking, climbing routes I know and love, and remembering that feeling.