Youth is gifted with boredom. You constantly seek new experiences to escape it, and boredom itself can spark that search. As you mature, boredom fades. Those moments of inactivity rarely visit me now, and when they do, I welcome them as a chance to breathe.
In getting bored your mind also wanders more. I feel that less, and that leads to my small gestures of dissatisfaction staying with me more. Don't think a fight with someone, but rather negotiating a date, and getting one later than I was expecting. Does it matter? Not at all, and yet it's hard to shake that feeling, which is not even an intense one, but somehow it keeps lingering, refusing to fade.