Frivolous information

The Sherlock Holmes character did not know anything about astronomy: He refused to know and care that the earth travelled around the sun.

Holmes saw no use for this information because it would not help him solve crimes.

I remain both in admiration and in puzzlement about that stance: How could he know what information could be handy when?

I gather everything I can: Revelling in the joy of frivolous information without hope of any use for it.

It is fun.