Absolutely right! I had a wonderful relationship with a lady a few years ago - and if I hadn't talked to her about my 'sub' side, I would never have realiesd that she had a Domme side...and she had never found a male sub to play with.
There's always a 50/50 chance in life (better than most odds) and it will either be a 'yes' or a 'no'...but you won't know until you talk about it.