When to stop?

This is a repositing from my personal site: www.thegameengineer.com/2011/11/10/m-a-d-m-a-n-8-%E2%80%93-when-to-stop/

A fellow programmer once commented that anyone over the age of 30 should not be working in the games industry. I believe his comment included something about security physically removing anyone on their 30th birthday them from the building and marching them out into the forest and leaving them there. Of course at that moment in time i just so happened to be in my early 30′s so I was very interested in his reasons for this statement.

A bit of discussion later and it turns out he considered the age difference between the game maker and the game player to be too great by the time someone gets to 30.

Obviously I completely disagree with this perspective but it did raise an interesting question, when should one stop working in the games industry?

So far I have…

When you stop learning new things.

When you no longer enjoy making games.

When you no longer get excited about pushing the limits.

When you stop playing games.