| Quote #1
"Oh, I wouldn't read that if I were you," said the manager lightly, looking to see what Harry was staring at. "You'll start seeing death omens everywhere. It's enough to frighten anyone to death." (4.1.28)
Do you happen to be paranoid that people are actually out to get you? In Harry's case, the paranoia is probably justified, but the novel seems to indicate that paranoia in general is a problem. See Trelawney's obsession with death omens, or Snape's willingness to see conspiracies everywhere due his long-festering hatred of Lupin and friends.
| Quote #2
Harry lay listening to the muffled shouting next door and wondered why he didn't feel more scared. Sirius Black had murdered thirteen people with one curse [...] But Harry happened to agree wholeheartedly with Mrs. Weasley that the safest place on earth was wherever Albus Dumbledore happened to be. (4.3.49)
Harry is probably experiencing some degree of shock here – he wonders why he isn't afraid, which implies a sort of detachment from his own feelings. But he also uses his unwavering trust in Dumbledore to combat his fear.
| Quote #3
No, in all the thing that bothered Harry most was the fact that his chances of visiting Hogsmeade now looked like zero. (4.3.51)
The Hogsmeade field trip plotline is probably the most normal in the entire book. The novel overall deals with some dark stuff – murder, imprisonment, death, traumatic memories, and so on. But the Hogsmeade stuff really helps to show Harry's age. Instead of being concerned about the lunatic killer coming to get him, Harry focuses on a different kind of fear: the fear that he won't get to go to Hogsmeade like "everyone else."