Try the Stroop Test: better than coffee to wake the brain

The Stroop Test is a psychological task of your mental vitality and flexibility. Quick! Say aloud as fast as you can what colour you see in every word, NOT the word you read, just the colour.

It’s a lot more challenging than it might seem. If you want to time yourself, check out this link. The first test will ask you to read the words. The second test will ask you to say the colours.  
http://faculty.washington.edu/chudler/java/ready.html

Then you can compare your score with my score:
Test 1: 9.21 sec
Test 2: 15.6 sec

Why? I don’t know... seemed like a fun idea at the time.