Explanation: You were thinking so hard that your brain had to draw a little extra energy from the Aether and because of that you created a gravitational anomaly that cause the water to travel up instead of down the shower wall...
http://www.geocities.com/ResearchTri...hinktank/2272/

That might help you understand.

According to quantum mechanics it could be possible (Except for the part about your brain because its probably tapioca pudding you damn druggie!)