Pretty much all mammalian babies are cuddly and mostly delightful. It's our nature. Speaking to polar bears specifically, because they have nasty-butt mothers who will rip you to shreds and feed you to said cuddly babies if you get too close. The babies don't need to be self-protective because they have an enforcer nearby. read more
You will often see mothers with only one cub, but most likely they had more but one of the cubs died. The cubs stay with their mother for 2–3 years. After the 2nd year with their mother some might leave, or some might leave the following spring after hibernating together. read more