Good Riddles

Question: I cannot be seen, cannot be felt,
Cannot be heard, cannot be smelt.
I lie behind stars and under hills,
And empty holes I fill.
I come first and follow after,
End life, kill laughter.

What am I?

Question: Hold me by the neck and I won't mind,
if I get wrong I just need a good wind.
If you want me you better pick wisely,
just use your ears and I'll follow you blindly.

What am I?

Question: A town only has one barber (he is male). The barber only shaves all of the people who do not shave themselves.

So who shaves the barber?

Question: A man was shot while in his car. The person who shot him was outside of the car. However, all the windows were up and the doors locked. There were no holes in the car though.

How was he shot?

Question: Little Johnny's teacher asks him, "If I gave you two cats, then two more, and two more cats; how many would you have?"

Little Johnny replies, "Seven!"

His teacher asks him again more slowly, "If I gave you two cats, then two more, and two more cats; how many would you have?"

But again Little Johnny replies, "Seven!"

Next she asks, "If I get two cats, then two more, and two more cats; how many would I have?"

Little Johnny replies, "Six!"

"Good Job Johnny! Now if I gave you two cats, then two more, and two more cats; how many would you have?"

Johnny thinks for a second, "Seven."

But Johnny is not wrong. Why?