One thing I have missed as an introvert is the "people watching" aspect. I don't need to be at the centre of things and don't enjoy big social occasions, but do enjoy walking around a bustling city, taking in the atmosphere. It feels like the world has stood still (or at least slowed) and that has made just my normal day-to-day less interesting.
Introverts aren't disinterested in society - they just like to experience it differently to extraverts.