The "why" phase

Jack has entered the "why" phase. He will now ask me questions and after every answer instead of asking "why?" he asks, "How come?" which to me is just a fancy "why?" The only thing that can stop the barrage of questions is distraction. Other popular phrases these days include: "I have a question for you," "I'm so glad I found you," "Look Mommy, it's a baby brother!" No Mommy/Daddy "We don't throw ___Toys_____" or whatever else we toss. "Look it's a baby, he's sooooo cute"