David Attenborough has documented many species on our planet, but an in-depth study of the luggage waddler would be a welcome addition to his oeuvre.
In Attenborough's defence, I can accept that he, like most of us, would seek refuge from these frustrating creatures, but there's at least one on every flight.
They bumble along, laden with acquisitions, like walking - and often loud-talking - human department stores.
The less fortunate will strike them on narrow airport passageways. Inevitably you will be hurrying to a plane gate. You cast a panicky eye about the scene, willing an alternative travelator to be within cooee, but this is not a James Bond film. There is no escape. You're stuck behind them, like tailgating an articulated lorry going 30km/h on a single-lane open road.
The species is also prone to perspiration, and can give the impression of being midway through a session of SAS endurance training.
These people ignore the No. 1 rule of luggage etiquette: only pack what you can physically carry. Can't do it? Ring a courier.
Last year my family raced against the clock across London to make the Eurostar at St Pancras station. After a beep test of a journey, we strolled on to the platform brimming with relief. This turned to incredulity when confronted with fitting our backpacks into the carriage.
I spent about 10 minutes marrying bales of Samsonite so there was room for two humble 60-litre canvas sacks.
If the train had struck an emergency while chunnelling to Calais, I dreaded fighting for our freedom through a sea of Louis Vuitton armoires.
My other pet hate is on flights. Stories abound of punitive action if carry-on luggage in any way exceeds the dimensions of a modest duffel bag. Yet somehow, presumably through the gift of the gab, these creatures shuffle on with enough inventory to survive on Noah's Ark. I'd wager even Santa would be impressed with the volume they can get through transit screening checks.
Surely implicit rules apply to luggage economy.
1. Brown shoes are more versatile than black, unless you've got plans to wear a tux.
2. Men, take one suit; and women, a dress or trouser suit for social occasions.
3. Muster enough energy and you can survive a short (or possibly long) trip without exfoliant, moisturiser and a bathroom cabinet of apothecarial potions.
4. Any flight is manageable with a book/magazine/ newspaper, jersey, water bottle, laptop, phone and myriad inflight entertainment options. Surely that's all you need on board?
5. Say "no" to millinery unless it scrunches well, or you're off to the Melbourne Cup.
If you can't fit what you want into 20kg or thereabouts, you've got a serious first-world problem, and Sir David may be preparing a voiceover on you sometime soon.