...discover everything except the obvious.

"Women have wonderful instincts about thing. They can discover everything except the obvious." -Oscar Wilde; An Ideal Husband

...to keep one's wife happy...

"Only two things are necessary to keep one's wife happy. One is to let her think she is having her own way, and the other is to let her have it." -Lyndon B Johnson

...apple and serpent.

"Woman is at once apple and serpent." -Heinrich Heine

Know her mind...

"Know her mind and you can have her body, know her heart and you have her soul." -Anonymous