And his knowledge remained woefully incomplete, Harry! That which Voldemort does not value, he takes no trouble to comprehend. Of house-elves and children's tales, of love, loyalty, and innocence, Voldemort knows and understands nothing. Nothing. That they all have a power beyond his own, a power beyond the reach of any magic, is a truth he has never grasped...

What's most important in a friendship? Tolerance and loyalty.

But Colin's only understanding of love was of limitless loyalty, boundless tolerance:

Such loyalty is admirable, of course,” said Scrimgeour, who seemed to be restraining his irritation with difficulty, “but Dumbledore is gone, Harry. He’s gone.” “He will only be gone from the school when none here are loyal to him,” said Harry, smiling in spite of himself.