I'm not saying this is easy though.
For me it is more of a humbling feeling than disturbing.
isn't that just an elaborate way to say 'give up'? I asked religious friends of mine about what god _is_, and the common answer is that it's beyond human understanding.
I don't believe that people should take things on faith, and accept that anything is beyond understanding.
Accepting that we don't understand something is a first and very necessary step to even realising there's something to understand. Believing that we have the answer (eg "God made the universe!") is exactly what shuts down scientific inquiry and makes people 'give up'. I'm saying literally the opposite of that - we have to realise there's something to out there to learn in order to try and learn it.
On the contrary, it was belief in the creator that opened up scientific inquiry in the minds of Johannes Kepler etc.
That the universe was not chaotic, but created by a personal being, led them to think there must be some order to it that could be studied.
His comment wasn't at all about giving up, honestly the exact opposite. It was about avoiding/managing the disturbed/dreadful feelings that commonly accompany the thoughts and work in this domain.
Similarly, we have limitations to what we can observe and measure. We strive to continuously make improvements, but we also need to accept that not all questions will be answered within our lifetimes, and unless civilization collapses, schoolchildren will have a more complete understanding of the nature of the universe in 300 years than we do.