My little guy (15 months) still doesn't do this because he is too busy figuring out how things work. He slams doors to hear them and bounce back open again. My dad is making him a special one that won't hurt his fingers. He climbs under the sink to see how the pipes work. He wants to take apart my vacuum cleaner. But, he doesn't know one body part and only says out and Uh-oh which means grandma. He will say something that sounds like Mama when he is crying, but only then. So, each kid is different. I'll bet you'll have fun with the next step of his fun development.