I feel this howl. I found that sales work was forming relationships so that you could make promises, personal promises. And what drove me out of it was that, beyond a certain point, there was no way I could guarantee that the promises I was making would be met. There was too much uncertainty, too much risk. But the client, in their heart, wanted you to look them in the eye and say "we'll get it done". Real sales people could do that and then go home to dinner and bed and a good sleep. I would do that and then go home and stare at the ceiling for 12 hours.