I started reading this fantasy novel on a friend's recommendation. In the book, a young man is raised in a household where all the men are manly and like to fight, but the main character is a sensitive sort who doesn't want to slog around in armor and deflower wenches. He just wants to read and play his lute. It's a lot like this Ray Stevens song, actually.
This is a pretty good setup for a fantasy novel. Obviously the young man will flee his overbearing family and find his way in the world, probably discovering that he has magical powers and will save the world or something. Standard, but usually interesting.
Well, the young man does flee, sort of. But before he finally blows that manly popsicle stand, he sits around a lot and thinks to himself about his shitty situation and how everyone hates him and it all sucks.
For about eighty pages.
Eighty-odd pages of this kid whining and throwing a 24/7 self-pity party. I hung on, hoping maybe he would actually do something besides act like a little bitch, and it finally seems he might be about to perform some actions of some kind, so I'm still reading. It's a near thing, though. I say he has ten pages to stop pissing me off before I give up (which sucks, because this is a trilogy and I bought all three books at once, I'd hate to have wasted the money).
Now Patricia, you say. This is realistic; there are people in this world who complain and feel sorry for themselves without ever doing anything to change their situations.
Yes, there are people like that in the world. These people are a giant pain in the ass. If I meet people like this, we rarely stay acquainted long. Most people can't stand these sorts of whiners, so you definitely don't want your main character to be one of them. Besides being annoying, they're also boring.
Even if your characters aren't necessarily whining, readers don't need (or want) to be treated to a constant internal monologue. In another fantasy series I only finished one book of, every time something happened to a character, they spent at least one paragraph reflecting on what had happened to them and how tragic/amusing/bizarre it was. It completely interrupted the flow of the story, and was the main reason I never read more of the series.
It's not wrong for your characters to reflect on the events of the book (or even complain about it a little- key word, little) but a line or two, maybe the odd short paragraph, is more than enough. I speak from experience as a reader and as a writer; I myself tend to have my characters ramble on and over-explain their emotions and actions. When revision time comes around, I cut loads of that stuff. And my writing is better for it.
So remember: we want to know how your characters feel and what they think...just not for eighty pages at a time.