A baby bird--sparrow, robin, you pick--is hanging out in its nest really happy and comforted. Mom is away grabbing food, squawking at other birds, you pick. While Mom is away, another bird visits and says "Hey, Baby Bird, your mom has moved to a different nest. Sorry about that." Another well-intentioned Momma Bird brings some food so Baby Bird won't go hungry. And Baby Bird eats, but the food tastes like crap because it's not Mom's food. The other Momma Bird doesn't know that Baby Bird likes her worms cut up diagonally, kind of chewed up first, and served in a very specific way. And Baby Bird cries because she knows that she'll never get her worms fed to her in quite the same way as Mom fed them to her ever again.
Baby Bird doesn't know if she should stay in this Nest of Betrayal or jump out and try to find her Mom's new nest. Mom isn't dead, thank goodness, she's just inaccessible. But Baby Bird stands at the edge of the nest and it's a loooooooooooong way down. And she knows that she needs to stay where she is. So she lays at the edge of the nest and she cries and cries and cries, for days. She sends a Friend Bird with a message to her Mom. "Why did you leave?" And she waits, and she cries, and she waits and cries. Other birds watch and shake their little bird heads. They don't get it--their Moms flew away and they're fine, it's how the natural order of things works, after all!
And then, Friend Bird comes with a message from Mom! Baby Bird chirps and chirps and chirps, Mom didn't leave...she got kicked out of the nest too. But it's all okay, Mom says, because soon Baby Bird will be grown up enough to leave the nest and when she is, they can get together for, you know, worm-coffee and worm-cocktails. And though nothing will be the same, it's not the ending that Baby Bird thought it would be. And Baby Bird is so happy...still sad in the loss of what was--but, as the other birds have said, it's the natural order. Things change, and Baby Bird can fight it or learn to accept it.
So Baby Bird spends a little more time on the edge of the nest--but now she's looking out rather than down. She knows eventually she'll need to jump, and she better know the lay of the land before she flies away.