How should i understand "Stored up kamma"?

It's funny I read this, because I was just talking about this with a friend the other day (though not in this philosophical framework).

Both him and I have been addicted to opiates, I have been clean of them for 2 years now and he is just starting to take seriously the concept of never doing them again. He was talking about how he wishes he'd never started, that he would go back in time and change it if he could, but I know for myself that if it hadn't been opiates it would have been something. There are booby traps in the soul, is what I told him.

Some experiences, you just have to go through because that is who you are. The partner who ruined your life but was too awesome in bed to refuse. The improbable business venture that ended in bankruptcy, but seemed too irresistibly lucrative. Opiates. These kinds of things are printed on your soul at birth, part of the fascination mechanism that drives your curiosity, appetite, and love of life. Without these drives, there is no reason to exist. But packaged with each one is a booby trap, and the only way to disarm the trap is to spring it and survive the consequences.

Like the Man said, though...there is no use thinking too hard about how it works.

It should be understood as it is said:

Whenever you perform a volitional action, the volition leaves its imprint on the mental continuum, where it remains as a stored up potency. When the stored up kamma meets with conditions favorable to its maturation, it awakens from its dormant state and triggers off some effect that brings due compensation for the original action.

Anything else is mere speculation and does not lead to liberation, but to clinging and craving on views.

If you feel that the answer to the question will lead you closer to liberation, meditate on the question and you will eventually experience it. Once you experience it, you will answer it. Once you answer it, liberation will be closer.

It doesn't need to be understood. Instead, look at your wanting, craving, to understand, learn, have an explanation. Understanding the totality of karma is not part of the Noble Eightfold path and will not lead you to cessation. The extent to which one should or is able to understand karma is experienced directly in the practice, beyond this for unenlightened beings is mere conjecture.

In the buddhist texts, 'storing up of kamma' is described best by the Pali word vipāka, which is most commonly translated as the 'result', 'ripening' or 'effect' of kamma.

The Buddha says (AN 6.63):

"And what is the result of kamma? The result of kamma is of three sorts, I tell you: that which arises right here & now, that which arises later [in this lifetime], and that which arises following that. This is called the result of kamma."

We don't need to understand the mechanics for this - in fact, as you have said yourself, the Buddha encouraged us to avoid speculating on it. But we can start asking questions about our actions and their results. There is plenty written about it, but I will offer a few questions to perhaps start you thinking about it in a practical way:

• Do my actions in the present moment have any effect on the future?
• Is there any pattern I can experience in these effects?
• Do skilful actions lead to good results, and vice versa?
• What's the problem with harming others, or stealing?
• What happens to this mind as a result? Is there any effect beyond the present moment?

Alternatively, we can read what the Buddha said about what is skilful and unskilful, and take it as a 'working hypothesis'. Then see for ourselves the effect of our actions...

I was just reminded of the wanting to understand kamma and how pondering about it is not relevant for liberation.

I then remembered "The Four Imponderables" where the Buddha taught that the workings of kamma should not be thought about since it hinders and distracts one from the practice.

"Pondering over the four acinteyya is a hindrance to the attainment of liberation"

"Therefore, o monks, do not brood over [any of these views] Such brooding, O monks, is senseless, has nothing to do with genuine pure conduct (s. ādibrahmacariyaka-sīla), does not lead to aversion, detachment, extinction, nor to peace, to full comprehension, enlightenment and Nibbāna, etc"