...about a minute ago. While eating his oranges after dinner, he suddenly said:
When it was 6:09, I finished half of my 4th slice of orange, so I ate 3.5 slices of oranges.
3.5 times 2 is 7, and 2 is the first prime number.
The last digit of 6:09 is 9, and 9 minus 7 is 2, and 2 is the first prime number.