What's the tipping point from being interested in aviation to becoming a bit of a nerd?

  • Downloading an app so I can find out where passing planes have come from and where they're going?
  • Choosing a longer layover so I can fly on a specific type of aircraft?
  • Booking flights specifically for the type of aircraft in operation?
  • Going to an airport specifically to watch planes coming in and out?

I've never done the last one. On a recent flight there was a group of men together whose entire trip was focussed on plane spotting. They didn't even leave the airport, and they were using long lenses and binoculars to read the registrations on planes too far away to see clearly. That might be a bit much.