What was the most impactful moment in Man's Search for Meaning?

For me, a most impactful moment is when a fellow prisoner rouses the others to come outside and view a sunset. Frankl describes the scene as follows:

Standing outside we saw . . . the whole sky alive with clouds of ever-changing shapes and colors, from steel blue to blood red. The desolate grey mud huts provided a sharp contrast, while the puddles on the muddy ground reflected the glowing sky. Then, after minutes of moving silence, one prisoner said to another, "How beautiful the world could be!"

This moves me because it shows that even at a place as horrible as Auschwitz, the human spirit couldn't be entirely crushed or eradicated. The beauty of nature also could not be stamped out, despite the barbed wire, crowding, and ugliness of the surroundings. Human beings in the worst of situations—a situation set up to be hell on earth and to make life as miserable as possible—were still able to enjoy a brief moment of contemplating the beauty of nature.
This moment helps support Frankl's thesis that human beings do better when they can find purpose and meaning. Even at Auschwitz, a prisoner could transcend his surrounding for a moment to appreciate the possibility of a beautiful world. This inspires me with joy at what the human spirit is capable of and encourages me to appreciate the small graces all around me.
Of course, different people will be impacted by different moments, but this is the one that sticks with me.