This is a trend on deviantart.com, but I thought we'd bring it to Fiestafan, since it seems like we got some people who can draw on here.
http://aprillaman.com/images/meme.jpg
What you basically do is draw a past you, whatever age, like age 6 and age 18. Then you just summarize both ages.
Example.
The art doesn't have to be magnificent and detailed. They're just fun to look at.