So you have dreams of starting a business. You also have a long list of potential downsides of following that passion, including perhaps significant financial and personal costs and a lizard-brain terror of failure and rejection. Poverty, divorce, and shame are hardly small fears, so let's be realistic, after you have your financial ducks in a row and sit down for a heart-to-heart with your spouse, what can you set against your remaining doubts to balance out your terror and actually make a move towards your entrepreneurial dream?

How about research? Each of us only gets one life's worth of experiences to learn from, but luckily we don't have to arrive at the end of our years in order to learn what we're likely to regret. A professor at the Kellogg School of Management has rounded up the wisdom of others to determine which regrets haunt people the most and which failures end up bothering us less in the long run.

The research team polled nearly 400 Americans about their regrets and found some startling patterns, a couple of which are relevant to entrepreneurs and a few which are not. Romantic regret was the most frequently cited, which may be a healthy reminder around Valentine's Day but isn't exactly pertinent to your start-up dreams. Another broad pattern very much is, however. In the long-term, what you fail to do bothers you far more than what you tried but screwed up, it seems. Kellogg Insight reports:

Research by Victoria Medvec, a professor of management and organizations at the Kellogg School, had previously established a connection between time and regret: The more time that has passed since an event, the more likely people are to focus on what they failed to do, rather than what they actually did. "Lost opportunities linger in our memory longer," [Neal J. Roese, a professor of marketing at the Kellogg School of Management] puts it. That is because people can quickly rationalize their actual actions, even when they went wrong. But for a possible action that was never taken, "there are so many ways in which you can see different things you could have done," he explains.

He illustrates the concept with a romantic example-;asking someone for a date. In remembering an unsuccessful attempt, an unlucky suitor might think, "I asked this person out on a date, she shot me down, it's done." But if he never even tried, the suitor might ponder all sorts of scenarios: "What if I had asked her when I saw her in the hallway? What if I had phoned right after we first met? What if I had sent flowers?"

The lesson clearly extends beyond daters to entrepreneurs. The evidence suggests that eventually you'll be far more troubled by not having given your entrepreneurial dreams a go than by your any imperfect efforts to start a business.

And if you're looking for more big-picture thinking about what's truly of value in life, be advised that meditations on regret are somewhat in vogue at the moment with big name media outlets from the New York Times to the UK Guardian running stories on what other people's regrets have to teach us. Pondering people's painful but unfixable errors may not be cheery, but if you have the stomach for it, reading about mistakes made by others could help you avoid similar regrets later down the line.