By feeling positive and hopeful, I will attract more of these positive emotions.

Moods are partly self-feeding, and the mechanism is behavioural rather than magical.

An hour of feeling reasonably all right is an hour in which you text somebody back, make a plan for Saturday, say yes to the thing. A fortnight later those replies and plans return to you as company, and company generates more of the same. The loop is slow and entirely real.

None of which makes a flat week a failure of effort. It only means the good hours do more work than they get credit for, and are worth protecting on the days they turn up.