The fact that The Hobbit is such a lighthearted family-friendly book, especially when compared to LOTR, actually breaks my heart when you consider that it is Bilbo’s writing. That journey was anything but a fun trip for him. He went through real dangers and horrifying moments. He saw violence for the first time. At the end of it, he lost his love. And he went home traumatized, heartbroken, and forever changed.
Yet when he wrote the story down, he emphasized the more successful and fun parts, and glossed over the depth of his pain and grief when the losses happened (even leaving Fíli and Kíli’s deaths to a throwaway line.)
Because what else could he have done? Nobody else could possibly understand his pain. Bilbo wasn’t like Frodo. He didn’t have a Sam who he shared the experience with and could talk to about it every day afterward, to help him work through writing down the details of the darker parts of the story. And his other friends lived far away and could only visit occasionally.
And the hobbit children were all full of wonder about Elves and dwarves and trolls, so he put the focus on that.
I feel like that was his way of dealing with his trauma.