What is “letdown”

A let down is essentially when the milk fills your ducts and is ready for feeding.

My letdown tingles. When I feel it, I know my milk will come out soon. I feel it when my baby is not on my breast. Like when my breasts get too full at night, or when they leak in public.

It’s a pulling sensation feeling in the breast basically signaling that it’s full or when the baby cries, i experience this

Is it normal to not experience it at all? Like I won’t notice my breast is full until I see them in the mirror or actually feel them w my hands. Unless maybe I’ve been asleep when it happens

I don't notice any sensation i just notice when they're hard and feel heavy