Remember your first bike? Not your motorcycle or 10-speed. Think back before that ... to the little bike with three wheels and pedals on the front wheel with a metal frame and streamers hanging from the handle grips.
The bike that you could ride on the sidewalk- your trike. If you were feeling really cool, you'd let your little sister or brother stand on the "bumper" and catch a ride along with you.
Here's a tricycle coloring book page for all you early easy riders to color.