Explain why the spectrum of life must appear in a particular sequence (Witty answers please)?

Question

Explain why the spectrum of life must appear in a particular sequence (Witty answers please)?

Answer 1

Since we exist within the space-time continuum, the arrow of time is always pointed toward the future.

Ergo, we can change the future by actions in the present, but we cannot change the past.

However, we can continually change our perception of what occurred in the past.  That mental construct would create a virtual arrow of time which subverts reality.