A Question on Threstals

So I'm rereading the Order of the Phoenix and I was thinking about the threstals and I couldn't figure out why Harry could just now see them. He was in the room when his parents were murdered right? So maybe I just can't remember them ever explaining why or I'm not far enough in seeing as how Harry has just seen the threstals but I don't recall the reason why he can only see them after Cedric's death.

Does anyone else wonder this or is it explained?

Harry was a baby...most things as a baby...you really cant remember it until you hit about 4 or 5...thats when a baby actually starts to remember stuff really really good. But basically...I think he just cant really remember his mother dying...and then agian...he was in his crib...he most likely really didnt even see it.

But what about when he's near the Dementors in Prisoner of Azkaban? He can hear and remember his mother dying. Is that something just caused by the dementors or an actual memory that they brought up?

Its to make them relive something horrible....just because he doesnt remember it doesnt mean it didnt happen. He also dreams about that in the first book, remember? I still dream of stuff from when I was a baby...but that doesnt mean I can actually remember it...

Good point.

Thanks, I get it a lot better now (: