Disclaimer: Nope, still not mine.
2: Love
It was an idea that had always puzzled him.
Maybe it was due to his life before his death – a dark and squalid existence at best. Most who came to the Soul Society did not keep most of their memories, if any – the Twelfth suspected it had to do with the trauma of death. However, for others that same trauma bought the memories up vividly. It didn't matter.
He was 95% sure, prior to his death, that "love" was an alien concept.
Granny had loved him, although the senile old woman thought he was her true grandson. He cared for her in his own way, awkwardly as a new foundling, then more as he aged, though rarely demonstratively.
He had cared for Momo deeply, as a sister. She had loved Aizen. Had loved, did love, couldn't seem to stop loving the cold-blooded bastard, no matter who it came from. Was that real love?
If it was, it scared him.
Long conversations with Hyorinmaru hadn't helped much; the blade spirit had a very different perception of emotions and how they worked. To him, love was being stroked with a whetstone.
It wasn't until he met the Kurosaki family that he really started to understand what "love" really was. Kurosaki Isshin, the wily old bastard, was not only a role model for his children, but an unwitting one for an adopted Captain.
Then again, if "love" was sobbing on his hands and knees in front of a wall-sized picture of his deceased wife, he wasn't even sure he'd ever figure the World of the Living out.