What the Rav said:
When the moon is at its smallest, then it’s the closest to the sun.
When the moon is completely full, then it’s farthest away from the sun.
So too, with man.
When a person is completely cowered, then his heart is broken, and then he’s the closest to Hashem.
And, when a person is full, then he’s full of arrogance, and then he’s the farthest from Hashem.
Nowadays (perhaps always), we place great importance on being the best, being first, being on top, being the greatest.
That may work in the physical world (although, it often doesn’t).
But, it doesn’t work in the spiritual world – in Hashem’s world. (The real world.)
There, being the ‘best’ is likely to be the ‘worst’ place to find yourself. Greatness brings arrogance with it and pushes a person far from Hashem.
Conversely, difficulties and being brought low, brings humility with it – and draws a person closer to Hashem.
I don’t know anyone that wants to be brought down low. But, if that’s where we find ourselves, we can take comfort in knowing that it’s davka from that place, we can get much closer to Hashem.