Never happens, does it?
Barring femur fractures, persistent shoaling or forgetting your gloves, as long as you continue to pedal, happy little serotonins will continue to dominate the skull cavity like ants dominate a dropped peanut butter, nutella and honey sandwich.
BONUS TIP: In case of glumness, look down. Check that is a bike you are riding, not a swivel chair. If it has four or five tiny wheels, it is probably a swivel chair. Continue sadfacing until it's time to commute. If you look down and your work chair has two big wheels, check whether riding a bike is in fact your profession. If it is, and you are glum, go fuck yourself. No really.