I've always regretted not being able to sing harmony. I believe my problem is that I overthink it. I can usually hear what the harmony should/could be, but somewhere between brain and mouth, it becomes its own beast. Too bad, since I have a passably dulcet voice.
I have a nice pair of bronze candlesticks which I keep polished. My neighbour has the same sticks but doesn't bother to polish. My two candlesticks are bright and shiny. My neighbour has a dulcet.