That is exactly as it should be. If doorknobs fascinate you, for heavens sake, take photographs of doorknobs. Or clouds, or ...
I once saw a wonderful book based on an unusual theme, "Outhouses"; another on *wonderful* graffitti in the Greenwich Village area of New York....
Hell, look at Siskand.

The guy made an AMAZING image of peeling paint!

Remember, you can find beauty in the least of things....