You have the ability to evaluate the situation before you dedicate yourself to a decision. The time allocated to do this can minimize disruption, reduce dissappointment, and decrease the amount of time wasted when making a poor decision for your particular situation.
A decision is a commitment to act. And unfortunately when you make that decision, you are stuck with it and have to deal with any positive or negative experiences that comes with it. That said, you must be prepared to embrace the outcome and realize everyone that is involved or it affects.
If you make the commitment for a job and then on the first day, after 40+ hours of being trained for the role, you decide it isn't for you because you think you should go back to school...EVALUATE this before you start! The reality is, the person that just trained you 40+hours probably doesn't have 40+hours to waste...and if they do, they don't want to waste it on you.
If you decide to have children and then choose that parenting isn't for you...guess what, you signed up for it and leaving them without someone to guide, teach, and mentor them isn't fair to them. If you don't want to be a parent, evaluate this before hand and choose not to have kids.
Plain and Simple.
When you make a decision, face what comes with it (whether you like it or not). And if that means to take more time to evaluate before you dedicate yourself...do just that!