Good to Bad Mood and Vice Versa

What takes you from a good mood into an instant bad mood? What about the other way around?

Here it is for me.

I'm in a good mood. 
I walk through the kitchen and whack my baby toe on the baseboard.
Instant bad mood.

I'm in a good mood.
Come home from a night at book club to find the kitchen in worse shape than when I left home - dirty dishes everywhere, food on the stove, lunch boxes unopened from the day.
Instand bad mood.

I'm in a good mood.
I go to the bathroom and realize that the person before me took the last bit of toilet paper and didn't replace the role. Even though the cupboard with extra rolls is RIGHT THERE.
Instant bad mood.

I'm in a bad mood.
My husband makes a gentle joke about my grumpiness and tries to cheer me up. I start to laugh at myself.
Instant(ish) good(ish) mood.

I'm in a bad mood.
I dig around in the pocket of a jacket or in my purse and discover cash I didn't know I had.
Instant good mood.

I'm in a bad mood.
A dear friend from who lives far away calls me just to catch up and I actually have time to talk.
Instant good mood.

I'm in a bad mood.
I come home from work or some other errand and find that people at home have started dinner or taken out the trash or emptied the dishwasher or FOLDED THE LAUNDRY or done some needed yard work.
Instant good mood.