Simple Line Puzzle

This is a fun little diversion I learned a long time ago. It's extremely simple, and it can be played anywhere you have a pen and paper and any time you have even a minute or two to kill.

The puzzle

With your pen and paper, sketch the puzzle "board" as follows:

You can re-draw instances of that design as many times as you need to. PROTIP: You're gonna need to.

Objective

Cross every line segment once and only once with one single, continuous line. That's it! You can start and end your line anywhere you like.

For reference, in the image below, each red line between any two black dots is a segment, and it must be crossed once. You don't have to draw the black dots -- I illustrate them here just so you understand what I'm describing.

Example

Here's an example of what an attempt might look like (an unsuccessful one in this case):

The silly blue arrows indicate which line segments I missed with this attempt.

Good luck, and have fun!

If you'd like to submit a solution, email it to me - I'd love to see it!