There is a trick to the third jhana, which I have regained and lost many times over the years. And that is where the "resting" of one's "I" is: in the mind, or in the underlying consciousness/awareness. The trouble with a busy life is the default is to rest one's I-hood in the mind. But, the real I is not the mind, but the awareness that's behind it.
Nice insight, that is what I find as well. I also found that if I were to try and conceptualize that "I", then it is a thought as well... So now I think of it more as a verb rather a noun... It is like riding the charisms or being "aware", instead of an "I" that you can point to... A bit like a buoy floating on the water as the waves go up and down, up and down...
It's a bit like a speed camera pointed towards a road for me. So I see the busy life as the swarms of traffic going to and fro on the road... waves of pleasure rise when you see a car you like, waves of pain rise when you see all the smoke polluting the place... but they are all just mental activities and perceptions of whatever sensory experience you have.
The cognition is like the road, containing all the thought-waves. They just rise and fall away... And I also find that both observer and the observed rise and fall as dualities, as a pair. If there is nothing, there is nothing to observe, nor an observer to observe it. But out of nothing always arises a something, impermanent, which is observed, and then it dies away.... Then something else rises to take its place. I don't know if I'm making any sense, just typing this out from what I feel. Even the "I", or ego-sense is something observable... perhaps that's what I'm trying to say. There's this thought... or sense that is heavy in gravity... it pulls identification towards it. It tries to pull the physical body as the "I"... or things that are pleasant as "I"... But yet it separates things, saying that "that is not I". It's like a very subtle form of clinging to me.
It is just like how our physical bodies are made out of atoms and molecules... carbon, hydrogen, oxygen, and so on... but they are also found elsewhere in the universe... and just because we gather these compounds within a body bag, we call it "I".. but it is simply because our field of sensation stops at the skin. And when the sensation of the body drops... it feels expansive... you're not the body bag anymore... the self-identification becomes 'finer' and finer... the "sensation" goes on and on past the skin, as if I become larger. I don't know if this helps or is accurate, but I am sure Jhanananda will be clearer...