No matter what your original purpose is, it will be interesting to suddenly receive an email from yourself in 10 or even 20 years. Maybe 20 years is too long, so let's take 10 years as an example. Think about yourself 10 years ago, you will find that your life in 10 years is almost unpredictable; think about the Internet 10 years ago again (if you were online at that time), you will find that its changes in the past ten years are tremendous, and you don't dare to predict what it will be like in 10 years. It is this uncertainty that makes the whole thing fun.