Looking back on their lives, people tend to regret the things they didn’t do, rather than those things they did do.  It’s the chances they didn’t take or the opportunities they allowed to go by that they lament.

Human nature makes us risk avoidant.  We prefer that which we perceive as safe instead of anything risky.  The known is much more appealing than the unknown.  So your innate tendency will be to avoid those opportunities where success isn’t guaranteed.