Let's start with something simple. Take your hand off your keyboard or mouse and look at the proportions of your index finger.
Hold your hand up to the screen. Don't be shy!
Each section of your index finger, from the tip to the base of the wrist, is larger than the preceding one by about the Fibonacci ratio of 1.618, also fitting the Fibonacci numbers 2, 3, 5 and 8. By this scale, your fingernail is 1 unit in length.
Curiously enough, you also have 2 hands, each with 5 digits, and your 8 fingers are each comprised of 3 sections. All Fibonacci numbers!
The ratio of your forearm to hand is Phi. Your hand creates a golden section in relation to your arm, as the ratio of your forearm to your hand is also 1.618, the Divine Proportion.
Phi - The Golden Number