What is blue but does not weigh very much?

Light Blue

I tried to draw a picture of a pencil, but I couldn't find the point.

I'm reading a book about anti-gravity.

It's impossible to put down!

I was at the park with my kids, and we saw a guy playing fetch with his dog. The dog was really fast and could catch the ball in mid-air. I was impressed and asked the owner how he trained his dog to be so agile.

He said it was a paws-itive reinforcement