How did you feel in the end? A worthwhile adventure? How did it work out web you came home? Was that 40k for one or two? I will have 40k saved up by sept.
A few thoughts…
It’s not for everyone, but if it’s possible for you, I would strongly recommend you consider looking into Peace Corps or another similar long-term volunteer gig, or even an English teaching job. Travel is great, but actually living as a part of a community is an experience that will challenge you and teach you more about yourself than you could imagine. In practical terms, at the end of extended travel you’ll likely be broke with some good memories. At the end of a Peace Corps service, you will have $6,000-$7,000, a language or two under your belt, federal hiring preference, two years of excellent career experience, preferential access to special grad school programs and fellowships, one of the best career networks you could dream of, a very helpful career center, and in no small number of cases, a spouse (I just came back from a Peace Corps wedding, yay!). I know you have been interested in going back to school- a lot of volunteers are able to take online classes to clear their prerequisites. Of course, what is most important is that there is a desperate global need for skilled teachers and instructors.
If something so structured isn’t for you, do give some thought on how to spin your trip. If you can’t come up with a good narrative, future employers are going to assume you spent the year popping pills and picking up on gap year girls on Khao San road. Employers don’t tend to look too kindly on bumming around and taking pickup English teaching and barkeep work. So look into opportunities to do substantial volunteer work, become fluent in a language, write book or make a movie, or anything that brings some focus and ambition into your trip.
Finally, I’d suggest dropping the “round the world” focus and instead choose 2-3 regions you want to really get to know. A year seems like a long time, but the world is a big place. For a trip like this, it’d be a shame to do it “if it’s Tuesday, this must be Rome” style. Instead, you’ll probably want a loose itinerary that is flexible enough that you can spend a week or three on a particularly nice beach if it strikes your fancy, you won’t throw everything off when you inevitably need a rest after drinking some bad water, and you’ll be able to duck out of a country if you are getting sick of it… You’ll probably want to plan your first week in a region and your last, and leave the rest up to what strikes your fancy. And this kind of travel takes time. To give some examples, I spent three months in India alone, and I still had entire regions I didn’t get to. It took me a month to get from Bamako to Timbuktu and back. Zambia and Zimbabwe was a month long trip for me, and it felt rushed. So try to refine your focus and figure out where you want to spend your time.
Some questions to ask: Are you going to focus on low-income countries, or is Europe and Japan the like in the mix as well? If so that will cost more money. Will you be staying in hotels, hostels, coach surfing, or camping? If you are not camping, don’t bring a ton of campy-supplies. Do you have any food restrictions to work around? Will visa fees be in your budget (they can add up!). Are you more of a “go to a place and stay there a week” kind of person, or more into long overland journeys that cut across a swath of continent? Will you be entirely independent, or will you want to join a group or other organized travel in some areas? How will weather fit in to your plans? It will be so much easier to pack if you are staying in roughly similar climates over the year. Are you more into nature/cities/adventure/cultural experiences?
Cost will vary significantly based on: what countries you visit, if you stay in big cities or explore the countryside, if you want to do lots of organized activities and things that involve admission fees (they can add up really fast), if you are willing to self-cater or eat at street stalls, how many plane rides you plan to take compared with how much you will rely on local ground transit, if you need things like AC and hot water in your rooms, how often you plan to drink or engage in other expensive vices (lots of places can get pretty boring in the evening, and you may find yourself in bars more than you’d be at home,) how much special travel gear you think you need (and you can get away without most of it), etc, etc.
India and China are extremely inexpensive. Japan is extremely expensive. Lots of countries are kind of unintuitive- very poor countries can be cheap if they have some tourist infrastructure serving local people, but very poor countries get obscenely expensive when they do not have that local tourism and all their facilities are set up for business travelers and dignitaries.
Last bit of advice- pack light! You can live for a year with the same stuff you can live for a week with. Leave that junk home!
it was fantastic. but then again, i could happily travel forever. imho exploring new places and experience new mentalities is something everyone should be able to do.
when we came back my wife picked up her old job, it took me a couple months to find work. the 40k was for 2, but obviously not all costs will be halved.
even sven has a lot of good advice, i’d definitely emphasize to just plan the beginning of your trip and let things happen more freeform afterward. it’s good to do research before you visit places and have to goals in mind, but to be flexible on timing and see what actually happens – some places you love and stay longer in, you meet people and your path changes etc. most regions, asia, south america etc, have low cost airlines where you can buy tickets last minute and explore.
Thank you both. I think I am reaching the conclusion that this kind of trip will only occur for me if some of my other options don’t pan out. The decisions to make in life is so crazy sometimes. 
Pshaw, so many naysayers. Like yourself I’ve had a longing to make a round the world excursion, and in 2011 I finally made a go at it (I was 33 at the time). I started out in Germany and made a counter-clockwise spiral, visiting as many countries as I could. I took trains everywhere and stayed at the cheapest places listed on hotels.com that weren’t complete fleabags. The longest I stayed in one place was a week. I found that you can see pretty much everything worthwhile in a city in only a day or two.
I got all the way to Istanbul by train, then flew to Bangkok, Thailand and continued on bus through Cambodia until I made it to Vietnam. Then I flew to Tokyo where I hooked up for a few weeks with a girl I had known in my childhood. Afterward, with nearly three months of travel under my belt, I flew on home.
In total I spent around $11,000. I don’t know how long you’ll be gone or where exactly you’ll be going, but perhaps that’ll give you some ideas.
First off, you’re not too old. 30 is just a baby. But if you feel too old to mess with the teenage or early-20s backpacker scene, there’s an increasing market for what have become known as flashpackers. There are actually two definitions of the word. One is youngsters who carry with them a bunch of high-tech gadgets. But the other definition is one I see used increasingly in Thailand and similar destinations: Somewhat older guys with a little money saved up and who want the backpacker experience but with a certain level of comfort. More and more guesthouses are going slightly upscale to accommodate these travelers. Google the term for more info if you think this could be the ticket for you.