Why arabs and especially egyptians think they won the 1973 war against Israel?

Maybe it's cultural thing. I remember reading in a book about ancient Egypt that the Egyptians might have used to depict wars that they have fought as though the won although they didn't. And that might be the reason why the Israelites exodus from Egypt wasn't found to be depicted explicitly in the Egyptian antiquity. There was a finding that said that there used to be Canaanites living in there, though, according to the book.