Movies
Get in a good mood. How hard is it to decide to be in a good mood and be in a good mood?
— Lloyd • Say Anything...

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker treats a good mood as something you can simply choose, and asks why that should be hard. It's half instruction, half challenge, with a slightly impatient breeziness. The repeated phrasing makes the idea sound almost absurdly simple, like flipping a light switch.
Context reviewed