I tease them about something I call "border privilege" when I fly with someone who is a relaxed traveller who arrives just before check-in closes. It is possible that a traveller was born with access to a passport with a high ranking.

If you don't know what that is, you're probably a holder of a passport that is high on the Henley passport index, which is a ranking of countries in terms of travel freedom. The ability to cross national boundaries with, at best, a sense of excitement and, at worst, mild annoyance, is what you have if you have a high passport rank.

Britons are going to find out a few things about border privilege when they find out what happens after the UK leaves the EU. It was only a nation that viewed freedom of travel as an entitlement that threw it away. If you didn't grow up with border privilege, you will know that without it travel is an obstacle course.

The passport at the top of the index allows the holder to visit almost 200 countries without a visa. The Sudanese one I was born with must be passed through the eye of a needle before being allowed to enter most countries. There are almost unscalable walls of bureaucracy and suspicion faced by applicants.

I used to be so afraid of travel falling through at the 11th hour that I wouldn't make any plans until I was in Canada. I only booked tickets at the last minute because I knew it was too late for anything to go wrong. I missed the bedsides of ill relatives, the celebrations of friends and family, and too many work and training opportunities because my visa applications were held up for weeks and months.

The holder of a low ranking passport is at constant risk of falling down trapdoors in the middle of a journey. A visa detail overlooked by a border official meant I was summoned, having just landed in Riyadh, into a room of angry Saudi border officials who scolded me and sent me back on the next flight. I had to pay the price of the return flight before I could leave the airport. When I was pulled into secondary processing in the US with no explanation and no recourse, where I was left for so long without information or updates, it probably amounted to some sort of illegal detaining.

The British passport has fallen out of the top spot. The new normal is being described as ominous. With more of a series of hurdles that others are used to, travel to and within Europe is becoming unpredictable and expensive. The domino effect of the introduction of a single stamp to enter the EU is what makes it sound like a small thing.

Consistency is no longer present in this reality. British visitors to Spain may need proof of funds to cover their stay, as well as a return ticket, in order to enter the country. Regardless of the requirements, the adequacy of your evidence is to be assessed by a single guard. All travel permits, both those that require only a stamp and those that require an involved visa process, are subject to different versions of the same brief sentence.

Someone with a low-ranking passport will tell you that in all interactions with this border official you need to keep your counsel, in the knowledge that this guard who has your passport in their hands is the most powerful person in your life. They have the ability to make laws on the spot and plunge you into financial ruin. Things can get worse even if they are bad.

It's important to remember that you are lucky to have got this far, lucky to have the paperwork and means to travel, and lucky that you have the skill and physical ability to negotiate an unforeseen obstacle.

I recount these experiences with no bad feelings. I sat next to an elderly woman in a wheelchair who was being yelled at at a US airport for not being able to speak enough English to answer questions about her visit. The work her family had done to get her into the country had been wiped out by a new requirement.

The most important lesson you will learn is that border officials are free to make their own decisions. They can be poorly informed, under-resourced, or unable to keep up with border policy changes, and yet they are part of a large and messy border policing machine.

British travelers will get an extra kick. Your grievances will be trivialised by the people who promote the UK's exit from the European Union. Being unable to afford holidays to our nearest neighbours is one of the gripes of a privileged few in a country trying to take back control of its own borders.

The benefits that we have lost can be clawed back by those who have the most money and time. For the rest of us, it's a good idea to have a paper of supporting documents and a very early arrival at the airport.

  • Nesrine has a column for the Guardian.