By live, I mean to say you saw it as it happened, not that you were physically present.
No idea what categories this goes in. It can be a personally cool moment, or an objectively cool moment.
Obviously I’ll never forget Super Bowl 52. The 2008 Summer Olympics - Men’s 4x100 freestyle was absolutely electric. Landon Donovan’s goal against Algeria had me doing laps around the house after ripping my shirt off. Crazy what sports can do to us.