What's Up With Moods?

Why do we go to bed feeling sad sometimes?
Other times with the same set of circumstances it all feels OK.

Birds were singing today. The sun was shining. I bought plants. Children were jumping barefoot on the tramp. Cold cereal was for dinner. And everyone got their chores done, though not cheerfully.

So what's up with moods? Why feel heavy hearted in the face of all that?

Is it realizing I've already gained 35 pounds and still have 14 weeks to go?
Is it my friend going through a divorce that seems so unfair and so eternally tragic?
Is it children whining over chores?
Is it not having had a real meal in three days?
Is it that the mess of a crazy week and a weekend away is all still in every corner of the house?
Is it the $70 I spent on plants and seeds with the weak hope that I'll grow more than that in garden produce? And the even weaker hope that my children will eat any of it?
Is it concern that Dallin carries such a heavy burden to provide for us and pay for this house and continue our comfortable lifestyle complete with piano lessons and store-bought hot dog buns?
Is it worry about when and where Dallin will find a job?
Is it guilt that I am not doing anything to bring in income?
Is it self-absorption?
Is it realizing that my favorite non-Brooks person turns 40 in three days and it's too late to do anything more than say, "You're my favorite"?
Is it that when I decided to have one of those beautiful slow-down moments of watching my kids play and being nearby that it disrupted them and it all ended in arguments and bedtime?
Is it missing my husband who is gone and will be for most of May?
Is it not liking my haircut?
Is it distance from family?
Distance from the ocean?
Distance from my goals?

Maybe it's not enough sleep. That was always my mother's solution--"It will look better in the morning." I've found it to be true, but still,

what's up with tonight?