Budget backpacking isn't for everyone. Neither is long-term travel – some folks just wont like it, and there is nothing wrong with that. Budget travel takes a lot of patience and it also can put you in some less-than-ideal situations. So, if you are thinking about hitting the road sometime soon you should make sure you're mentally prepared for when the road hits back. Because it will.
You are going to eat crappy food as a backpacker – especially if you are vegan/vegetarian or have specific food restrictions. Being on a budget means you will be sticking to cheap food, and that isn't always the best/tastiest/healthiest. Sure, you can get some amazing, cheap street food in places like South East Asia but in many countries of the world your food budget will fall short. Heck, the food itself will fall short in many countries of the world. Accept the fact you wont always be eating a balanced breakfast. There will be times when you are hangry, times when you crave food from home, and times you regret eating that mystery meal. C'est la vie.
Health and Safety
You will get sick on the road. It's inevitable. At some point you will eat bad food or drink unfamiliar water and find yourself embracing the porcelain throne. I've puked my guts out in Chengdu, and dodged a dietary bullet in Mongolia. In both cases I ended up getting familiar with the hostel bathroom. I was lucky – these were just single incidents. Some folks get sick for the duration of their trip, curtailing their very ability to enjoy it. And that's if you're lucky. Throw in poisonous plants and animals, dangerous drivers, and disease-carrying insects and you have yourself a recipe for adventure. Come prepared with travel insurance, some emergency meds, and an acceptance that you will get the shits. Or, at the very least, that you will have to listen to your dorm-mates have the shits...which is almost as bad.
...or lack thereof. From jet-lagging flights to bumpy night busses to loud dorm rooms, sleep is sometimes hard to come by on the road. Even heavy sleepers will want to bring ear plugs and an eye cover on their backpacking expeditions. Light sleepers, like myself, are just generally fucked. There will always be some idiot coming in at 3am who turns the lights on (maybe because he is running to the toilet...) so shrug it off and get used to catching some zzz's when you can...if you can.
Like the asshole who turns the light on at 3am, you will ever be confronted by douchebags and their douchbagery while backpacking. It's just like life back home – just because you hop down to South America doesn't mean you will be free from idiots. Idiots travel too, and they bring their moronic tendencies with them...and those tendencies are generally enhanced abroad by cheap booze and the yolo-inducing buzz travel oft foments. They are the kind of dicks and dickettes who buy these bracelets and wander Thailand in herds. Shrug 'em off as best you can and maybe they will take their matching muscle shirts elsewhere.
Unless you are solely hitchhiking and camping, travel takes a pretty hard toll on ol' Mother Nature. Excessive flying (including ridiculous mileage runs!) drinking bottled water, buying things with excess packaging (vs shopping in bulk at home) are all actions that harm this pretty planet of ours. On top of that, many destinations offer attractions that harm animals, too. From petting drugged tigers to watching dolphin shows to riding captive elephants, many countries embrace animal tourism to the detriment of those very animals. PLEASE, if you are going to travel do your best to be responsible and ethical. It is the very least you can do.
In The End...
Travel is a privilege, but it isn't for everyone. If you're going to hit the road and explore this lovely little world of ours just make sure to bring a sense of humour and a pocket full of patience. You'll need both.