Cross-posted from the Quora thread that I replied to earlier:
I come from a lower middle class family and my rule of thumb with personal finances is to always have a minimum of 6 months worth of cash saved up at all times. So if the fecal matter collides with the ventilating appliance, you have enough fallback funds to tide you over for at least half a year while you're rebuilding your life.
When I joined my first team startup 5 years ago I pushed that threshold to 12 months. (I already had a solo-proprietorship that was doing reasonably well at the time.) I had saved up about 1M PhP as a personal hedge to keep myself alive in case the startup didn't pan out. I was 26, and had just moved out of my parents' house for good the year before.
As luck would have it, roughly 12 months later, I had less than 16,000 PhP to my name, and the rent for the apartment I had so proudly rented was 14,500. (So yes, I came within PhP1,500 or $35 of total personal bankruptcy. And if you include the balance on my credit card, I was actually in the red by over PhP200,000.)
Our little 7-man team managed to weather that particularly bad bunch of months and bounce back. We started hitting over PhP1M gross monthly, and about a year after my personal low point, we were acquired by Winston Damarillo and Exist. (A mildly happy ending, but that was just the prologue for my current challenge with Infinite.ly.)
Sorry for the verbose response, but I needed to set up my answers properly, because I happen to think that the question of "what it takes" can be answered purely in practical terms. Here they are in handy list form:
1. Emotional will is one thing, but solid financial planning trumps that every day of the week. Being an entrepreneur is soul-crushing and ego-mangling, and fraught with disappointments, but ultimately what will make you quit is when your money runs out. You need to save up. Precisely how much is subjective, but a good way to look at it is to figure out your minimum monthly spend and multiply that by 12 months.
2. As a corollary to (1), I would also recommend living off your parents for as long as humanly possible. This is easy in the Philippines since we tend to stay with our folks until we get married anyway, so stick with this strategy. It may not be sexy or cool to still be going home to your mom after pitch meetings and tech demos, but this familial fallback is our singular advantage over our credit-card-wielding US counterparts. (That and the fact that you can get drunk for under $4.00 in this country.)
3. Don't wait for a great idea, look for great people. You've heard this one tons of times so I'm not gonna harp on it too much. A good idea does not a startup make. I joined my first team startup because I felt that they were a talented bunch. None of our early ideas panned out but we're still alive and kicking today, albeit with a different set of business cards. I also don't believe in solo entrepreneurship, which is why I emphasize "team" a lot. If you're genuinely talented and driven, people should be naturally drawn to you. If you can't even find a cofounder, that's pretty strong market feedback right there.
Bottom-line is that doing the startup thing is hard, but the reason why people play this game is because high-reward goes hand-in-hand with high-risk. It's rewarding to be working with really smart, talented people every day, and it's rewarding to go through the roller-coaster ride of startup financials, and it's rewarding to see people use and enjoy your products.
The risk is what draws people to it. Just make sure you've got some cash in the bank before you play.