In my experience, the generalization that "it" is about a "rush" isn't the case. For one thing, mountaineering at almost any level, but especially on 8k peaks,

In my experience, the generalization that "it" is about a "rush" isn't the case. For one thing, mountaineering at almost any level, but especially on 8k peaks, is a long, slow, march. There will be some moments that are a rush, but if one is interested in a rush then BASE jumping would be a lot more effective. The other thing is that mountaineering involves lots of specific skills - rock climbing, ice climbing, long unsupported approaches, self arrest, winter and extreme cold conditions, the ability to acclimate - all of these have to be put together to solve a problem: getting there and back in one piece. And that problem solving, combined with the ability to overcome the mind game of suffering is the motivation for all the mountaineers I know.