For the sake of performance I'd like the following change:

```Ruby
def upcoming_events
  Event.where(["date > ?", Date.today]
end

def events
  if @events.nil?
    rsvped_event_ids = Set.new(EventRsvp.where(user_uuid: self.uuid).map(&:event_id))
    @events = upcoming_events.include_if { |event| rsvped_event_ids.include?(event.event_id) }
  end
end

def events_without_rsvp
  upcoming_events - events
end
```