Cuddling a baby is a pleasing experience at first but running to a screaming infant's side over and over again, day after day, wears thin so parents tend to put something in the crib for the tot to play with. A teddy bear is a common choice and, when cuddled, it stimulates skin sensors so the baby is distracted from sensations of aloneness or growing pains or whatever but, just like adults tire of holding infants, so too do babies get bored with the same toy after awhile.
They start screaming again so parents place some other distracting object in the crib with them and that process occurs repeatedly until, soon enough, the little child begins looking for new and different things because they are more distracting than familiar objects. That curiosity becomes a lifelong venture as children, who make an early career out of pulling, twisting and ripping everything within reach, grow up to climb the highest mountain, dive to the bottom of the sea and try to fly to the stars to find out what it is all about.
From birth until death, the human species is intensely motivated by curiosity and, as most people know only too well, anytime humans are repeatedly prevented from satisfying their curiosity, it can be driven into a fever pitch that is entirely out of proportion to the real value of whatever has been withheld from the curious.