As with most members of this problematic list, the best way to avoid misusing the word passion is not to use it at all. The same holds for compassion, which, as you may come to see, is seldom sincere and amounts to little more than an invasion of another's privacy. This is not to say that these are bad words denoting bad deeds (for they are not); rather, the integrity needed to find the right word - to mean precisely what you say - demands virtue, which is a reward to everyone it touches.
Many folks seem unpleasantly surprised to learn that passion means suffering or endurance, for they tend to backpedal if caught using the word in another sense. It derives from the Late Latin -passionem (nominative -passio), which conveys a sense of pain - possibly even virtue - but not pleasure. This may explain the apparent oxymoron with which I began this essay and/or that latent hint of some vital difference between that sex which is passionate and that which is 'unusually exciting'.
Taking the word literally (which is always a good place to start), only sadists and masochists would use passion to describe joy. Though the pre-Latin root derives from a Proto-Indo-European verb for -to hurt, the Latinism concentrates on martyrdom. The endurance aspect of suffering suggests that it must be both long (duration) and hard (durable) to qualify as passion, as opposed to simply stubbing your toe or tolerating your mother in-law.
A funny thing happened on the way to the forum: the same Late Latin -passio was used to render the Greek pathos, a mere homonym with overtones of calamity (literally 'that which befalls') and the arousal of pity. The sense of passion as sexual arousal is less than 500 years old and that of enthusiasm, less than 400. Yet the so-called passion-flower gets it name from this same recent era - not because flowers are sex organs and not because passiflora is an aphrodisiac (which it is not), but for its resemblance to a crown of thorns.
I am a happy exponent of passion - anyone who knows me will confirm that I regard intentional suffering (and not martyrdom) as one of the three means by which to awaken and explore human potential. Meanwhile, passion is casually misunderstood and earnestly taken in vain, sometimes to absurd extremes, just as is compassion, whose true meaning is shared suffering and not sentimental pity. So when someone asks me, no matter how innocently, "Are you passionate about ... (fill in the blank)?", the word (not the thing!) sounds at once trite and vulgar.
I am a happy exponent of passion - anyone who knows me will confirm that I regard intentional suffering (and not martyrdom) as one of the three means by which to awaken and explore human potential. Meanwhile, passion is casually misunderstood and earnestly taken in vain, sometimes to absurd extremes, just as is compassion, whose true meaning is shared suffering and not sentimental pity. So when someone asks me, no matter how innocently, "Are you passionate about ... (fill in the blank)?", the word (not the thing!) sounds at once trite and vulgar.