I think the self-image or the worldly understanding of the self — the idea that “this is me,” “this is how I look,” “this is how I feel,” the complete set of ‘me’ — must be broken.
Once it breaks, the mind will no longer see our past deeds as something done by a fixed ‘self,’ because the mind’s idea of identity or individuality will be shattered.
Similarly, the mind will not get deluded by constructing a future, as there is no longer a complete or fixed sense of self.
The mind realizes that everything exists as different parts, not as one unified ‘I’.
As mind have this habbit to wonder in past and future during seating
The best way to approach this is:
Do your regular Ānāpānasati meditation while seated.
Throughout the day, while performing your daily duties, observe everything through the lens of Satipaṭṭhāna.
Before trying to break the self-image itself, I would suggest breaking the craving for self-image and the other underlying causes behind it. Many people can’t function without a self-image, and breaking it prematurely may lead to issues such as depersonalization. That’s not the case for noble ones (ariya), for whom the view of self (attadiṭṭhi) is uprooted without harm.
The Simile of the Baby is found in MN64 Mahāmālunkyasutta where the Buddha explains the difference between self-view (attadiṭṭhi) and the underlying tendency (anusaya) toward self-view. A non-noble baby (i.e., a non-sotāpanna) may even be born without explicit self-views, but they are still born with the tendency to form such views — and this unfolds within the first years of life as development progresses.
The Four Satipaṭṭhānas are very useful for overcoming these underlying tendencies. Complementary to them are the Gradual Training, as well as the development of Right Intention and Right Conduct outside the meditative context—through study, reflection, and daily life practice.
It is not surprising if at times we have resistance about anatta. Even the venerable Channa, who later became an arahat, knew the teaching about anatta but he shrunk back from it.
Saṁyutta Nikāya 22.90. Channa
The elder bhikkhus said to the Venerable Channa: “Form, friend Channa, is impermanent, feeling is impermanent, perception is impermanent, volitional formations are impermanent, consciousness is impermanent. Form is nonself, feeling is nonself, perception is nonself, volitional formations are nonself, consciousness is nonself. All formations are impermanent; all phenomena are nonself.”
Then it occurred to the Venerable Channa: “I too think in this way: ‘Form is impermanent … consciousness is impermanent. Form is nonself … consciousness is nonself. All formations are impermanent; all phenomena are nonself.’ But my mind does not launch out upon the stilling of all formations, the relinquishing of all acquisitions, the destruction of craving, dispassion, cessation, Nibbāna; nor does it acquire confidence, settle down, and resolve on it. Instead, agitation and clinging arise and the mind turns back, thinking: ‘But who is my self?’. But such does not happen to one who sees the Dhamma. So who can teach me the Dhamma in such a way that I might see the Dhamma?”
Personal Reflection on Anatta
When I first started to see that all elements arose and ceased, that there were only conditions with no self, no one controlling thinking or anything else, I found it unsettling, even frightening. I worried, ‘If I am not in control, maybe I might start doing bad things’. And ‘How can I be sure to attain if I can’t even control the next moment’. But this is simply the way things truly are, whether we understand it or not. Courage gradually builds alongside understanding of this truth, and with it comes a natural detachment from the wrong view of a self. There emerges a glimpse that there is no one who can make things happen, no one who can stop things from happening. This gradually brings a serenity based on letting go of wrong ideas about life—there is less struggle and more acquiescence to whatever comes.
Sometimes I would think, ‘Yes, I will just sit back and observe this,’ but that is still a subtle wrong path. There is not someone who can observe—understanding and awareness are themselves conditioned, and they are often absent. This too has to be known and accepted, the path is non-attachment all the way.
It should be noted that although the self is an illusion, there are still causes and effects and these are elucidated with great precision in the texts. It would be a grievous misinterpretation if we thought that anatta exempted us from the law of kamma. In fact the teaching on anatta and conditionality are intertwined, and so insight comes with knowledge that whatever is done, whether good or bad will bring its appropriate results.
I can add a little more. The way I see the development is not changing ourself to some idealised version of a Buddhist. Our personality is the outward presentation of aeons of accumulations.
Rather than struggling with our perceived weaknesses there can be understanding coming in that learns about the nature itself.
Thus developing the perception on anatta correctly should come with detachment— it is a relief actually to give up the struggle. Let panna, wisdom, perform its task of understanding naturally..