How important is inspiration to your intimate relationships?

I left my ex husband simply because he no longer inspired me and I no longer inspired him and it was reason enough for me to avoid such stagnation (despite having a child together) and I stand by my decision years later…I’ve been told plenty of times that I was selfish, that it’s not a good enough reason, etc…(eff that noise)...but what about you? how important is it to you to be intellectually challenged and inspired by your partner, to have them constantly grow and at a pace that’s in step with your own growth?