10. Underestimating the hell that is Heathrow
Speaking of London, it's easy to underestimate the several hundred miles of concourse you'll likely be obliged to traverse and the time-consuming security searches that create jumbled queues and make travelers look more like internment camp refugees than cosmopolitan jet setters.
Arriving anything less than two hours before an international flight is risky, but even a longer cushion can get dicey.
Imagine walking across a football stadium and you start to get an idea of the Andean trek from the Heathrow Express station to the swarm of travelers clamoring to get on lifts that will take them merely to their start of the Oz-like journey through Terminal 1.
11. Buying cheap flip-flops
You think, "I'm only gonna wear 'em for a week, I might not even take 'em home, why buy the good ones?"
The answer comes when you blow out a toe strap and shred the bottom of your foot a mile into a hike across the local lava beds.
And now you have to go back.
12. Fearing street food
No one wants to get sick on vacation, but why travel all the way to Thailand or Mexico and not eat the local grub?
The locals don't like food poisoning any more than you do. If they're in line, consider the place vetted and assume you're going to be fine.
(Cue angry commenters with the "I almost died from a tainted falafel" and "the locals are immune to bacteria" histrionics below.)
13. Buying a drum on the first day of a three-month trek across Asia
We know, this is the antithesis of travel mistake number two, but there are some balls and chains you really don't want to lug around the subcontinent.
Not because you'll make instant enemies with everyone in your hostel when they spy you struggling top-heavily into the dorm, but because a) you'll never play the thing, and b) you'll get back home, walk into the new Authentic Beats music shop that replaced your favorite bookstore while you were away and find 10 superior examples of your exact instrument.
14. Over-reliance on guidebooks
Making a travel plan using only your guidebook is like making a plan to stand in line at the bank for a week.
Guidebooks are great -- we use them all the time -- but it's best to pull just one or two suggestions per day from a guide that thousands of like-minded travelers have read or downloaded.
15. Not buying the full insurance policy
We're not a bunch of free spenders -- except when the boss whips out the company credit card at the pub -- but a lot of the mistakes on this list come down to adding a significant amount of stress to your life in the name of saving a few bucks.
If you actually end up needing the travel insurance you purchased (a move a significant percentage of our staff thinks is silly in the first place), you're going to want the full coverage.
Just because you're in a country where the beer is cheap, it doesn't mean the healthcare is.
That bargain insurance policy might pay for your flight home when you crash your motor scooter on a winding road in some island paradise.
But it won't cover the $5,000 in stitches and sponge baths you racked up during your three-day international hospital stay.
16. Obsessive photography