First, when Hagrid and Harry are leaving the hut on the rock, Harry asks Hagrid how he got there (as they steal the Dursley's boat). He responds that he flew? How? We learn later that Hagrid doesn't do brooms. He is too big for Thestrals, and usually has to ride Serious's motorcycle if he needs to fly...

So how did he really get there?

Next, Vernon and Petunia make a big gag of Platform 9 3/4 and how it doesn't exist. In Snapes memories, we learn that Petunia has actually been ON the platform when Lily left for school. No question here, just an observation.

In book 7, Hermione tells Ron and Harry that she has modified her parents' memories so they would move to Australia. Later, when asked if she knows how to do this, she responds that she hasn't done it but thinks she understands how it is done.

In book 7, Hermione tells Ron and Harry that she has modified her parents' memories so they would move to Australia. Later, when asked if she knows how to do this, she responds that she hasn't done it but thinks she understands how it is done.

Something I recently noticed when re-listening to the books, is that Harry sees the Thestrals for the first time when going up to school in OOTP, and we are told he only sees them then as you only see them after seeing someone die. However, at the end of goblet of fire it is mentioned that they get the carriages down to the train, and Harry doesn't see the Thestrals then, but this is after he has seen Cedric die, so in theory he should...

Next, Vernon and Petunia make a big gag of Platform 9 3/4 and how it doesn't exist. In Snapes memories, we learn that Petunia has actually been ON the platform when Lily left for school. No question here, just an observation.

"I just take the train from platform nine and three-quarters at eleven o'clock," he read.
His aunt and uncle stared.
"Platform what?"
"Nine and three-quarters."

"Have a good term," said Uncle Vernon with an even nastier smile. He left without another word. Harry turned and saw the Dursleys drive away. All three of them were laughing.

1. ..., but I think it is more likely that he used something like a portkey. We are not specifically told how Hagrid got there, but I think this would be an easy "problem" for JKR to fill if she had to.

Harry didn't actually see his parents die. JKR said this in an interview also. He was in his crib and didn't see it. Also, at that age he didn't really understand what was going on anyway. The understanding and acceptance of the death that the person sees is what allows them to see thestrals. Harry, at the end of GoF, hadn't had the moment when Cedric's death really sunk in. That happened over the summer between GoF and OotP, which is why he couldn't see thestrals at the end of book 4 but could at the beginning of book 5, and it's also why he couldn't see them at all before that point.

Has she actually commented on Harry not seeing Thestrals until OOTP fall/autumn, despite his parents dying when he was one? Because in the interview I recall, the question referred to his parents deaths, whereas her answer referred to Cedric's death! She may have gotten back to this at some other time, though.

However, in the interview I remember she made clear that she chose to let the realisation and acceptance of someone's death be the pivotal point at which you start seeing the Thestrals, because the other alternative would have to be to introduce them at the end of GOF, which she didn't want to do for a number of reasons. However, whether Harry saw his parents die or not, he definitely had had plenty of time to realise and accept that they were gone by the time he first comes to Hogwarts, so if acceptance plays such a big part, why didn't he see them from year one?

FAQS: Thestrals

Why could Harry see the Thestrals 'Order of the Phoenix'? Shouldn't he have been able to see them much earlier, because he saw his parents/Quirrell/Cedric die?

I’ve been asked this a lot. Harry didn’t see his parents die. He was in his cot at the time (he was just over a year old) and, as I say in ‘Philosopher’s Stone’, all he saw was a flash of green light. He didn’t see Quirrell’s death, either. Harry had passed out before Quirrell died and was only told about it by Dumbledore in the last chapter.

He did, however, witness the murder of Cedric, and it is this that makes him able to see the Thestrals at last. Why couldn’t he see the Thestrals on his trip back to the train station? Well, I didn’t want to start a new mystery, which would not be resolved for a long time, at the very end of the fourth book. I decided, therefore, that until Harry is over the first shock, and really feels what death means (ie, when he fully appreciates that Cedric is gone forever and that he can never come back, which takes time, whatever age you are) he would not be able to see the Thestrals. After two months away from school during which he has dwelled endlessly on his memories of the murder and had nightmares about it, the Thestrals have taken shape and form and he can see them quite clearly.