He was experiencing emotion completely unknown to him.
The two stood, locked in a deep gaze, fully experiencing what they found in each other's eyes.
I think I'm already experiencing that.
However, you're obviously experiencing something bizarre.
Napoleon was experiencing a feeling of depression like that of an ever- lucky gambler who, after recklessly flinging money about and always winning, suddenly just when he has calculated all the chances of the game, finds that the more he considers his play the more surely he loses.