are kids strong when they put in there all?

Why is it said that to a toddle or child, a grown-up can look super strong and almost a giant like? Or that they can even come off as intimidating even when they’re being very nice and they just do something like stand next to them, or pick them up? Is it really true that a adult can pick a child up with a single hand? What about in terms of strength, is it really true that an adult Can stop their punch mid air while picking up the child? how so given that the child is going at their hardest? couldn't the 7 year old also do the same to the adults punch mid air? How much different is the strength? is it really true that when playing and Arm wrestling, the adult can pick up the whole child with one hand?