You know you have played too much Penumbra when...

[Gharren]

...when you can survive any injury just with some painkillers.
...you decide to go somewhere to nowhere without food or water.
...you start to throw things around just for fun.
...you have stored dynamite in your drawers.
...you randomly mix chemicals to make an explosive.
...you open every drawer or locker you see.
...you collect notes from other people.