It essentially means that you act like the person you would like to be right now, even if you don't actually feel that way. Act like you have what you want in life, even if you don't.
For example, if you're feeling down about your marital situation, you act as if your H is not bothering you and that you are content to go about your business.
Say "Hi" pleasantly to him, even if you feel like you'd rather not.
Smile, even if you don't feel like smiling.
Anticipate that pleasant behavior will produce better outcomes, that sort of thing.
I am doing exactly this. It's so counter-intuitive as it feels like I'm making his life easier and it's easier for him to move on when he thinks I'm okay without him. It's hard to stop guilting him over his choices when my heart is broken and my kids are suffering but I know it will be better for my mental health no matter what.
