It has effected every one of us at one point or another in our lives. There is no foundation, rationale nor cure and when affected it's difficult to disguise.
The most common cause is after sexual relationships with an individual you no longer want sexual relations with. Their very being repulses you - the way they breath, a slight blemish, the way they hello or god forbid their touch. Other common causes include but are not limited to:
a) work mates whose opinions are irrelevant and whom you ignore at any cost
b) family members, particular old and / or extended who's smell never seems to leave
I'd never previously noticed that she has a hairy top lip, I know she's got a dark complexion but its almost like a full on moustache. As awesome as her body is that beauty spot on her forearm needs to be operated on, I think its actually grown since I met her.