I FOUND OUT WHO IS GOSSIP GIRL WHILE WATCHING THE 1ST EPISODE

So yes as the title says, I had a feeling that dan is gossip girl while watching episode 1 of season 1, i really don't care about spoilers so I when wanted to know if Serena and Dan end up together I googled it and that's how my suspicion got confirmed, so is it like an open truth? Were the watchers supposed to know it was him???

Also I'm on season 3 now and I find the show very boring now, give me some reasons to continue watching, I don't mind spoilers.