Short Version
The Long Version gives details, references, and develops the connection with orthodox Buddhism.

"The Right Understanding of Dukkha" is central to Buddhism. These days, Dukkha is usually understood as 'suffering'.

The First Truth - What is Dukkha?
In Buddha's time, the new invention of the spoked wooden cart wheel, was causing a cultural revolution. Buddha saw the connections: desire is self-perpetuating, and once the wheels start turning, then they turn with their own karmic momentum.

ancient wooden spoked wheel
The wheel has various symbolic uses in Buddhism. One of these is that ancient wooden wheels often squeaked, snagged, grinded, or wobbled, and the hub needed constant maintenance in order to run smoothly. Dukkha described when a wheel was problematic and not running smoothly.

But for Buddha, this was not a question of the literal meaning of the word Dukkha. In those days everyone knew what Dukkha meant. Buddha's question was what is the problem with life's wheel? What is not running smoothly?

In many texts, it is written that the Five Aggregates are Dukkha. The Aggregates are five umbrella terms which explain how we experience the world. They describe the process: manifest form, sensation, perception, concepts and consciousness. The Aggregates apply to all of our senses. They describe the way we sense life.

The process: manifest form, sensation, perception, concepts and consciousness is Dukkha.

The First Truth tells us: Our sensory apparatus is problematic.

The Second Truth - The Cause of Dukkha

What is the prime cause of our sensory wheels being problematic? Our sensory apparatus is influenced by pleasure and wanting.

If something is pleasurable, we want to repeat it. Even the smallest want we have, will lead to some form of repetition of the idea, and probably an actual repetition, or something similar. Pleasure defines our repetitious pre-set mindset.

Repetitions involve us in a timeline, they are not conducive to being now. And, once the repetitions start, once the wheels start turning; then they turn with their own karmic momentum. Repetitions are Karma.

The everyday sense of: "that craving which gives rise to fresh rebirth"; is "that wanting which leads to fresh repetition".

Attachment, clinging, and craving, – cycles, routines, habits, and karma – and also greed and closed mindedness - are all possible consequences of the repetitions.

Extreme forms of repetitious wanting like craving, have extreme consequences like suffering; and the simple truth behind this is that wanting leads to repetition.

Pleasure and Wanting lead to Repetitions

Please continue with Buddhism: The Third Truth and The Middle Way

Extract from Chapter Three : Buddhism