Tangential lives: everybody gets one. At any point in your life, you can chose to make the "other" choice, and live your life along that dimensional line until death, at which point, you return to your current life, at the point where you created the tangent, memories fully intact.

Side-effects may include feeling old before your time and dissatisfaction with your "real" life.

Note that the earlier you make the choice to tangentalize, the longer your alternate life will be (unless your alternate decision causes you to get his by a car), but waiting until later in life may yield better informed choices. Also, when you find that your parachute has a hole in it, you'll regret having already used up your tangent.