Not in the Mood? Make a Mental Transition
An important part of execution is managing transitions. That’s where the time gets wasted and the distractions rule. If you're not "in the mood” to transition to the top priority item on your list, you can waste a lot of time getting down to work.
To get out of the wrong mood, first you need to know, what mood or mental set do you want to transition to? If you're upset, maybe you want to calm down. If your brain is feeling sluggish, maybe you want to rev it up for thinking. If you are feeling distracted, maybe you want to zero in on your purpose.
Just noticing, "I'm not in the mood" won't help you get into a better state. You need to identify where you want to go. If in doubt—aim to go to a neutral state. It’s hard to go from upset to happy. But upset to neutral is not so difficult.
Once you know your goal, you can start taking baby steps in that direction. Little steps are important, because when you're unmotivated, big steps are a deal-breaker. But with a few little steps, you move yourself in the direction that is good for you, and it becomes easier to take the next ones.
For example, sometimes I feel bored and restless in the evening. I want to do something "fun," but in that mood, nothing sounds all that fun, even though I know, for example, that singing songs is enjoyable. So, now I have a procedure to transition out of the blahs with three small steps:
1) I move the guitar to the couch.
2) I pull out my songbook.
3) I tune the guitar.
I take these three steps without the slightest commitment to singing, but sure enough, by the time I've tuned the guitar, I figure, "why not sing a couple of songs?" After a couple of songs, I'm no longer feeling bored and restless. I might keep singing, or I might switch to some other recreational activity--but in any case, I've beat the blahs.