it's a good thing tears never show in the pouring rain

I almost never listen to the lyrics. but sometimes, just sometimes, I find a song which suits me best. and then I sigh. darn it, I say, they spilt the beans.
It's all about love, isn't it?
Vincent de Paul wrote about it, Mother Theresa did, Oscar Wilde as well, Shakespeare, oh boy, he wrote the most. But was there any of them right about love? Or could they have been terribly wrong? How do we know if we're right when everything else feels awfully wrong? And how do we protect ourselves against the "I wish I stayed"?