That's a way to increase the realism to the reader, if you want to get technical - you leave it [character] vague and you let the reader fill in the blanks with their imagination.
Nicholas SparksOur souls were one, if you must know and never shall they be apart; with splendid dawn, your face aglow i reach for you and find my heart
Nicholas SparksHe was thirty-one now, not too old, but old enough to be lonely. He hadn't dated since he'd been back here, hadn't met anyone who remotely interested him. It was his own fault, he knew. There was something that kept a distance between him and any woman who started to get close, something he wasn't sure he could change even if he tried. And sometimes in the moments right before sleep came, he wondered if he was destined to be alone forever.
Nicholas Sparks