maybe you're not attending these types of events with the right people?
i've always found family weddings to be super joyous, but i love the people i'm around. same for vacations, if i go with some good old friends or family, its always a wonderful time.
now, concerts or sporting events, i agree with you, but those are more 'passive' events where you are a spectator vs. a participant like in a wedding/vacation.