What does “mood struck” mean in the context below? Thanks in advance.

Here are some valuable things I learned from working part time jobs. Bosses can behave badly. Like the married restaurant owner who pinched me when **the mood struck** and whispered deeply inappropriate things in my ear. I was less traumatized than flabbergasted.

Question

What does “mood struck” mean in the context below? Thanks in advance.

Here are some valuable things I learned from working part time jobs. Bosses can behave badly. Like the married restaurant owner who pinched me when **the mood struck** and whispered deeply inappropriate things in my ear. I was less traumatized than flabbergasted.

Answer

A mood is a state of mind. You can have a bad mood or a good mood. This boss was in a mood to be a little naughty.

When you get in a mood all of a sudden, we say that it "strikes."

e.g. All of a sudden, the mood struck and I weeded the garden. 
LOL. No. That was Moira's example.

In your text the boss simply had a sudden impulse, and acted on it.

Answer

Example of 'when the mood struck/strikes etc.

When the mood strikes I weed the garden. It struck yesterday! I did some gardening.

That particular mood does not strike very often. That's the reason the garden is untidy!

Answer

whenever the restaurant owner felt like he/she is in the mood to pinch, they did it.
when your mood strikes you to do sth, you feel like you want to do it.