Some day you will die.
Lying on your sick bed about to breathe your last, you will be assailed by every kind of pain, your mind will be filled with fears and anxieties and you will not know where to go or what to do, only then you will realize you have not practiced well.
The Skandhas/aggregates (matter, sensations, conceptions, impulses, and consciousness) and the four elements in you will quickly disintegrate, and your consciousness will be pulled wherever your ancient, twisted karma leads it.
Impermanence does not hesitate.
Death will not wait.
You will not be able to extend your life by even a second.
How many thousands times more will you have to pass through the gates of birth and death.
If these words are challenging, even insulting, let them be an encouragement for you to change.
Do no accumulate unnecessary possessions.
Don't give up.
Still your mind, end wrong perceptions, concentrate and do not run after the objects of your senses.
Be determined not to let your days and months pass by wastefully.
-Zen Master Guishan
I read this quote on a youtube video of Mark Togni performing some fourth series Ashtanga. This quote really stuck with me. Death WILL NOT wait. Our days are numbered, and we really don't know when our number is up. It's too easy to let our days pass by with an attitude of "it can wait for tomorrow". What if tomorrow doesn't come? Do you want to repeat your same mistakes from this life in the next? The only thing that we can take from this world is consciousness. There are no material possessions that are coming with us. So do you want to exhaust your resources by building up material possessions or do you want to build up your consciousness and awareness? We are presented with that choice in every moment of our life, and it's not too late to change :)