MN44 explains sakkaya ditthi’s. There are 20 kinds. In my own words: one regards or views rupa, vedana, sanna, sankhara and vinnana to be Me, or mine, or in Me, or Me in rupa, vedana, sanna, sankhara and vinnana.
So, if, for example, pain arises there also arises almost immediately the longstandig habit of regarding or viewing or assuming this pain as my pain. That is a sakkaya ditthi arising. Viewing dukkha vedana as mine. That is literally explained as sakkaya ditthi.
‘I am this’, or ‘this i am’ is the general expression of sakkaya ditthi (SN22.89).
It is said in Abhidhamma commentary that this habit can only be uprooted by the (sotapanna) magga citta. Does that mean it happens over time or at once?
And if this sotapanna magga citta arises do we not notice or experience that? Do we not experience Nibbana, which is the object of the magga citta?
In other words, does the arising of the magga citta stay unnoticed? Do we not have some kind of experience?