OUCH X 100!!
Don’t know about you. I’ve never read any fancy parenting books, I’d NEVER, EVER, EVER leave a baby crying. Yidden are labeled Rachmanim, how it rubs against me. It should rub against any parent. And we’ve had the run, regulars, colicky. As I noted on a different thread, HaShem deals with a person as s/he does. When picking up a crying (undeserving) baby, say to HaShem, “look, my baby’s crying for no good reason, but I can’t stand to ignore it. You too, take note of our crying..”
Oh, btw, my children, Baruch HaShem, grew up – they don’t cry any more. They’re saturated (spoiled) with feelings of care and love etc., Baruch HaShem.