The past is a feral beast, one consumed with emotion and eager to ravage your heart and mind. It will bite, claw, and devour your present, it will frighten your future away and leave you trapped, alone and broken, as it continues to lay waste to your body. You wish to exile it, you send your best men to combat the creature and slay it, but all are felled themselves, becoming the beast's next meal, but you do not learn. You send more of your greatest and strongest to challenge the beast, and you watch as they are torn apart and feasted upon by the menacing monster. You weep and howl, you curse and screech! You want it gone and are soon consumed with emotions that are much like the beast's. You become angry and despairing. You hate it so you continue to unleash your mightiest to fight it, but, once more, they are killed and now reside within the beast's belly. And it stays! With the land a wreck, the people gone, why does such a foul thing continue to plague you when there in nothing left to destroy? Because you feed it. You feed it men every day and every day. You know this, you know yet you cannot stop. You send more warriors to their doom, and the beast grows with every mouthful of flesh. How do you defeat such a beast? You fire arrows and watch the cold steel tips impale the creature all over, drawing blood. You see it fall into its own crimson puddle with a deathly splash, only to gasp as the beast rises to its feet, unscathed. How do you rid yourself of an immortal? You stop feeding it. You lock all your loyal subjects within the stone walls of your castle! You raise the bridge and fill the moat with boiling water with scalding snakes that sliver up from it and into the sky! The beast cannot pass the hot water, it cannot jump through the blazing mist and steam. It cannot break down the walls, nor can it leap over them. Hungry and abandoned, the monster leaves your land to never return! What a joyous day it is!
The past, as mighty and towering as it may be, is still only the past. It cannot hurt you if you do not feed it. To dwell on the past only fattens the nefarious creature. To force yourself to forget will not yield results either, for exiling it will only make it want to return. You must make it known to the beast that there is nothing there for it so it will have no reason to come back. You must stand by and let it pass, do not dwell on it. When it comes, face it, think it over, and when it is ready to leave, let it. There is no shame in looking on the past, there is nothing wrong with thinking about it, but as soon as you obsess and dwell over it, as soon as you litter your heart and mind with regret, there is a problem. So when troubled, let the past come into your mind naturally and let it leave naturally. Only then can you truly rid yourself of it.