“Don't believe anything you read on the net. Except this. Well, including this, I suppose.”

Simplified Meaning:

It's saying that you should be skeptical about what you find on the internet, even the things that claim to be true. Think of it like this: imagine you hear a rumor at school that a new student was a movie star. It sounds exciting, but you shouldn't just believe it right away. You need to check if it's actually true by asking around or looking up trustworthy sources. For example, if someone tells you that eating carrots will give you superhuman vision, it might sound right because carrots are healthy. But before you believe it, you should look for scientific evidence. If you find out that carrots are good for your eyes but won’t give you super vision, you've used good judgment. In the same way, when you're online, make sure to double-check the facts from reliable sources before accepting them. By doing this, you'll be more informed and won't be easily misled. It's important to think critically about information, even if it's something you really want to believe or something that seems convincing at first glance.