Indeed a tough one to understand and put into practice. The moment "I" read the passage the question arose which part of my "I" wants to change? There are no immediate solutions to these puzzles but the practice of Vipassana provided some link : when everything is arising and passing away, so are the "I's". Having said this from a mind level the experience came while having tea. Each sip felt different and changed the taste with passing thoughts..the first one was "aha', towards half cup it was about finishing quickly and getting on to the day, also it meant a lot whether it was being shared with someone or it was in solitude. Upon deeper search within it was revealed that the wishes, desires that come up are arising to fulfill the Ego attached with each "I', which in turn will give rise to craving and aversion, depending upon the resultant action. Thus, the whole cycle continues. Hence, for now, for me its difficult to catch the real one as that too will pass away. So the practice under cultivation is being very authentic to each arising "I' and holding it with love and compassion. At those points of contact with the "I' when its accepted "as is" and loved, something heals within, the mask peels off on its own, effortlessly.