Anyone can come with an idea for a company. But not everyone can come up with one that’s both practical and worth quitting your job for.

Sources of start-up ideas can come from just about anywhere--a theme or problem from an entrepreneur’s daily life, an emerging trend, a gap in a specific market or a passion for helping others in an inventive way. It's not the source of the "aha" moment that seems to challenge entrepreneurs, though. The real struggle comes with the ability to find an idea that’s worth the toil of starting up.

That's why Daniel Gulati, a tech entrepreneur and author of Passion & Purpose: Stories from the Best and Brightest Young Business Leaders spent a month investigating where successful entrepreneurs found their ideas. He surveyed 50 founders in three different stages of company development (pre-funding, growth and acquired/gone public.)

After thorough research and detailed follow-up interviews with 15 founders, he came up with a list of the top five sources of now-thriving start-up concepts: 

1. I experienced a pain point in my life and wanted to solve it. 

2. I met someone talented and we started a company together. 

3. I have a special skill or passion, and I turned it into a business.

4. After working in an industry for a long time, I saw a customer need.

5. I researched many ideas and eventually narrowed it down to one. 

The most popular source by far is the pain-point motivator, says Gulati.This makes sense since starting a company requires long hours and seemingly endless focus. Both are likely much easier when you feel a personal connection to the purpose behind the company. Gulati explained that the key to this factor is understanding how much your own problems are worth. 

Neil Blumenthal offers a prime example. With his company, Warby Parker, he was able to solve a personal frustration--that is, spending too much on expensive glasses. He combined this concept with an initiateto help others in the process. (Warby Parker gives a pair of glasses to someone in need for every pair bought.)

Rent The Runway also launched based on a personal dilemma: Attaining designer clothes on a consistentbasis is not affordableor practical for young women. The solution was simple. Give women an option to rent rather than buy.

While you can draw from any of the sources on the list for your start-up idea, drawing from a passion and personal frustration--that happens to respectively inspire or annoy others as well--might be a good place to start.