Does every woman have lesbian thoughts?

Not every woman, no, but probably most women. Probably most men have gay thoughts, too. Most people are neither completely straight nor completely gay. Most people are at least slightly bisexual, even if they don't realize it, or try to repress it.

Human sexuality can be measured on a scale of 1 to 10, 1 being totally straight and 10 being totally gay. For example, I would describe myself as a 3: mostly straight, but with occasional lesbian thoughts.

But, even though most people are at least slightly bisexual, not everybody is. Some people are completely gay or completely straight.