Appamāda - What is it? How to practise it? Benefits? In this video, Ven. Yuttadhammo Bhikkhu says that the whole of the Buddhist teachings could be summarized as Appamāda (heedfulness), at the risk of oversimplification.

In the Mahaparinibbana Sutta (DN16), the Buddha conveyed the last message of his life:


  Then the Blessed One addressed the monks, "Now, then, monks, I exhort
  you: All fabrications are subject to decay. Bring about completion by
  being heedful." Those were the Tathagata's last words.


According to the Appamāda Sutta (SN3.17):


  "There is one quality, great king, that keeps both kinds of benefit
  secure — benefits in this life &amp; benefits in lives to come."
  
  "But what, lord, is that one quality...?"
  
  "Heedfulness, great king. Just as the footprints of all living
  beings with legs can be encompassed by the footprint of the elephant,
  and the elephant's footprint is declared to be supreme among them in
  terms of its great size; in the same way, heedfulness is the one
  quality that keeps both kinds of benefit secure — benefits in this
  life &amp; benefits in lives to come."


Questions:


What really is Appamāda (heedfulness)?
How does one practise Appamāda (heedfulness)?
What are the benefits of Appamāda (heedfulness)?
Why is this one of the most important concepts in Buddhism, that the Buddha chose this to be his last message?
What is the relationship between Appamāda (heedfulness) and mindfulness? This answer equates the two.
Pamada is a condition of a happily misbehaving child or a drunken person enjoying oneself too much. A type of silly joyful carelessness that assumes no concern or responsibility for results of one's actions. There are many translations of this word - laxity, sloppiness, but the one I find particularly insightful is "indulging".

Appamada then is a sober, grownup, calculated attitude to things. A grownup may relax a little, but never loses sight of what results will the actions bring. Hence the usual translation, heedfulness, or my preferrence -  "sobriety". 

One metaphor Buddhism uses a lot is that of intoxication. The three basic intoxicants of desire/obsession, negativity, and confusion/delusion cause the state of pamada, when one acts without proper regard for the consequences.

The practice of Appamada is certainly related to mindfulness, remaining aware and remembering the teaching at all times, but here the emphasis is on karma, or action and its expected result. Not only the physical action of course, but mental activity as well, including upadana, or fueling certain thoughts by giving them attention. We can either indulge in harmful thoughts uncontrollably, further fueling our intoxication, or be deliberate about our thinking, which leads to cessation of suffering. This last application of appamada can't be emphasized enough. 

Appamada means always staying in planned, deliberate, results-oriented frame of reference, as opposed to merely acting out one's emotions and impulses. Every time before we think or say or do something, we ask ourselves, what will this achieve?

So that's one aspect, always being deliberate, and the other aspect is not letting oneself get intoxicated. We get intoxicated every time we get aroused by the scent of an external source of joy, or by a particularly inspiring form of negativity. We get excited off balance by the thought of either reward or righteous anger. If we let ourselves get emotionally intoxicated all the time, we practically never spend time being emotionally sober, which makes us mentally weak. Instead, staying sober and collected requires a certain kind of strength and will power. In a way, you always keep your spine straight, your feet on the ground, your eyes open, your mouth shut. That's appamada, sobriety.