Do 你 think that everything l says is a lie?

l is very secretive, and when he 说 that he didn't suspect Light as Kira all the times he was lying. How do we know if the personality he's brought up in Death Note is just a fake? He may have pretending to like sweets, sit in an odd way, and hunch over, maybe at 心 he's just like Light. I mean l and Light are very similar, anyways. And if 你 read the one-shot, it 说 that he doesn't really care about justice, he was just bored. That's the strange thing about L, 你 don't know what's real what's not. He 说 himself that "he is a monster that lies."