Just because you can do one thing does not mean that you can do another thing that is similar.  To become great at something, you need practice and some innate talent (see October - Lesson 19).  Just because you're given the opportunity does not mean you will do a decent job.  In fact, you're more likely to be awful than awesome.

Example:

• Rebecca Black
• America's Next Top Model All-Stars making music videos
• Many viral videos
• Those so-called "triple threats"