I Can't Explain

My eldest son used to say that when he grew up he was going to marry me. Last night he and H came downstairs having played together without incident for a record-setting 20 minutes and he announced: "I really love H. When we grow up we can get married."
I suggested that he and his little brother could be best friends when they grew up instead. Why couldn't they get married he wondered out loud. Was it because boys had to marry girls?
No, that wasn't the reason I told him.
Can boys marry boys he asked.
Yes, but it's unusual I said. "Do you know what unusual means?"
"It's not happening all the time."
"That's right."
"But it happens sometimes."
"That's right."
"Do sometimes boys marry boys?"
"Sometimes they do, but you still can't marry your brother."
To make a long story less long, I went on to explain why brothers and sisters and cousins can't get married. That it's a better thing for a baby to have different genes (not the kind you wear) instead of similar genes which is what would happen if you married your relative. I reminded him of the talk we had about why he and his brother both had blue eyes (because mommy and daddy have blue eyes), and that babies might get sick if they have parents who are relatives.
None of this actually had anything to do with why he couldn't marry his brother since he and his brother wouldn't be able to have babies, but, thankfully he was distracted enough not to pick up on that.
Fifteen minutes later he asked me when daddy would be home.
"In a half hour. It's only 5:30."
"But it's so dark. Why is it so dark?"
"Because this time of year it gets dark early."
Gay marriage and hemophilia, those are topics I can tackle, but daylight savings time? How do I explain that?

song: I Can't Explain • artist: The Who