Do you remember the moon you asked about earlier? [Points towards it] It's large and gives off light, right? And it's far enough away that it can float like the birds.
The sun is like that, too. But right now it's near to the sun's bedtime. See? [Pointing now towards the fading light, at this point the sun is probably dipping behind the trees from the forest]
Tomorrow, it'll come back up and it'll be very bright and warm and... [well. you're sensitive to light, aren't you?]