When children are experienced as delightful, when that’s communicated through words & actions, children experience themselves as delightful & then they believe they are delightful.
The interaction will probably be forgotten but with repeated experiences of being a delight in the eyes of others, the belief that they’re delightful will be remembered.
In the thick of it, we won’t always experience our children as delightful. Parent/child relationships quite rightly feel fraught at times.
But those moments where we look at them with a big warm smile and communicate how glad we are that they exist, how glad we are that they’re ours, that’s where the real magic is.