The End Of Gatsby

I loved the book! So disappointed when Gatsby died though. I finished reading the book a week ago because once I started reading into chapter 6 I couldn't put it down. The only thing that I didn't get in the end was that Gatsby had a father, but denied it when he was alive. I don't get why he would say he was a orphan?! Can't wait to see the movie with Leonardo DiCaprio.