Thanks to thousands of reblogs and repins on Tumblr and Pinterest, the origin of this may never be known. It dates back at least till 2006 and perhaps earlier...

Take chances.

Tell the truth.

Say no.

Spend all your cash.

Get to know someone random.

Be random.

Say I love you.

Sing out loud.

Laugh at stupid jokes.

Cry.

Apologize.

Tell someone how much they mean to you.

Tell a jerk what you think.

Laugh till your stomach hurts.

Live life.

Regret NOTHING.

I've seen something like this way before 2006, see this old school Nike ad in Sports Illustrated featuring Barry Sanders:

I have a whole Manifestos stash for things like this.

You're right that there's a pattern to poems like this.

A computer could probably auto-generate such prose.