The carrot, the stick, and the scars they both leave...

I never really understood the meaning of the expression involving a proverbial carrot and stick. According to some the metaphor in the expression involves luring someone with a reward they will never get (namely, using a stick to hold a carrot in front of the person and pulling it back every time they reach it, making it impossible for them to get to it). Others argue that this expression symbolizes reward and punishment since, if the person acts as they should, they will be rewarded (carrot), but they will be punished if they act otherwise (stick). Thus, we have two scenarios: one where we blindly and futilely seek gratification and another where we face pain but have a chance at joy...However, which rules apply if we are the ones wielding the stick and carrot in front of someone else? Should we keep our distance while offering a carrot that person will never get, hence preventing them from ever being hit with the stick, or should we offer both the carrot and the stick, holding both equally firmly?

Physically, we are reminded of the pain we once went through with our scars. Small cuts that show us how we were hurt and supposedly prevent us from repeating the same mistake. Emotionally however, those scars apparently vanish only to randomly reappear causing more pain: a song which reminds us of someone long after we thought we forgot them, a place is transformed from an address to where we once met, and an object covered in dust is suddenly a gift you once gave or received. Nevertheless, we are only too happy to give emotions a second chance and hope never to be hurt in the same place again. We tell ourselves that life is too precious to waste a single second and should take advantage of every moment and opportunity, even if we might get hurt along the way. Thus, when we relive a situation by which we once were scarred, we use the carpe diem excuse clause to plunge head-first into a most probable repetition of our failure. Even so, this is inherent in our nature; after all, we are the only animals which trip twice on the same stone....but, what if the choice was not so much to prevent our own harm but to prevent hurting the other person? If we know for a fact we will scar someone we care for if we start a relationship, is it best to prevent the wound or trust the scar will serve as a reminder of an irreplaceable experience? Is carpe diem a valid alibi to inflict pain or is it our way to heal our own scars?