a sharp jab in the I

According to Heraclitus: "Everything flows and nothing is left (unchanged)". You cannot step in the same river twice. What does that imply re the current "me" (whoever that is) taking responsibility for actions performed by a previous "me" (whoever that was)?

There are major problems understanding or defining the "self/soul". For starters, there's the issue of where the self lives. Then there's the issue of whether the "I" that I am now is the same as the "I" of ten years ago, or a minute ago, or even the "I" in another memory or mind.

And then there's the issue of what "I" believe and what I perceive. Light travels very quickly (186,000 miles per second) but it still takes time for a photon to get from A to B. Everything I see, I see as it was in the past. By the time I become aware of what I am looking at, it is no longer the same thing as it was before. When I look through a telescope at, say, the nearest star (Proxima Centauri), I see Proxima Centari as it was 4.24 years ago. (Proxima Centauri is 4.24 light-years away from our sun, Sol.) So, the data on which a Self constructs reality, constructs itself, is old data. Not only is it old, it is unreliable data, very likely pertaining to that which no longer exists.

Some believe that the only time there is, is right now, the eternal moment. And that the eternal moment is all there is, was and ever will be. And that all that "I" am, have, do, know is part of or the whole of the eternal moment, per the "Tat Tvam Asi" ("you are that"/"I am that I am") of vedantic hinduism in which the soul (or consciousness if you prefer) is wholly or partially the ultimate reality, (whatever that means).

It's very difficult if not impossible to define exactly what we mean by the word "self". And that's because the Self is a slippery beast that shrugs off attempts to define it.