In case people actually come here to read my blog, I wanted to share the following fact I found out myself recently and wish I had known about.

When booking a round-trip ticket with any airline, and for whatever reason miss or skip the first leg of the trip but arrived at your destination by other means and want to fly back with your round-trip ticket, airlines will not allow this, because your trip is out of sequence.

If you don't know this you will be forced to buy a new ticket at the airport, which is pretty expensive, or not be able to travel at your planned travel date.

I recently traveled to germany, but had to leave earlier than planned. Since my original ticket/airline did not offer a flight at the desired date, or charged an exorbitant amount to change my original ticked, I decided to look for a cheaper one-way flight.

When my return date arrived, I was educated at the airport that I can not use any ticket out of sequence, ie. use leg n+1 of an itinerary without having used leg n