Toddler needs at least 15 hours of sleep a day

My son is 2 and he sleeps 7-7 and then 12-3 and sometimes we wake him up if he’s still asleep at 3. We keep worrying that the long nap will interfere with his bedtime, but… it… doesn’t? Is this insane?

For comparison, his little sister is 1 and needs less sleep than he does!

I asked his pediatrician who basically shrugged off the question and said I’m lucky to have kids who are good sleepers….