What's keeping you from greater success in life? It's probably not that you don't know what you need to do to reach your goals.

We all understand that if we want to be healthier and lose weight, we should say no to that second slice of cake and exercise more. If you want to get ahead at work, turning off the TV and learning a new skill or launching a side project instead is a great idea.

And yet some people seem to miraculously be able to make themselves do all these healthy but unpleasant things. They get up at 5am to go running, trade that cake for kale, keep disciplined schedules, and always make time for self-improvement. What sets these super achievers apart from the average Joe or Jane?

Your first guess is probably an outsized amount of willpower. But science says, your first guess is wrong.

According to a new study, what sets the highly self-disciplined apart from the rest of us isn't their ability to white knuckle their way through temptation, it's the wisdom to avoid it in the first place.

Just accept it, your self-control is terrible.

To figure this out, the team of researchers recruited 159 university students to keep detailed diaries of their efforts to reach their personal goals, how they responded to things that tempted them away from their goals, and how emotionally exhausted these efforts left them. The research team then followed up with the students to see who had actually achieved their stated goals.

Instead of finding that those who achieved their goals exercised more self-control than average, the scientists discovered that those who actually accomplished their goals reported experiencing less temptation.

Here's how they summed up their findings: "Against popular and scientific wisdom, effortful self-control did not appear to play a role in goal-pursuit, suggesting that the immediate positive consequences of exerting willpower do not translate into long-term goal success." Translation: slackers and achievers alike all have terrible self-control.

What's the takeaway then? The British Psychological Society's Research Digest Blog sums it up nicely: simply spend less mental energy on resisting temptation, and more on avoiding situations that are going to lead you astray.

"The key to success therefore is to avoid temptation in the first place. Avoid the grocery store when you're hungry. Don't leave the cookie jar on the side in the kitchen. Make your bedroom an iPad-free zone. Don't fight the devil on your shoulder, outwit him," writes the site's Christian Jarrett.