It depends on how that perfect entry was done, if it is pure lucky, that person won't value his perfect entry too much and can exit without mind about perfect exit price. In another opposite situation, if a perfect entry was chased intentionally and was taken eventually, it will more likely result in perfect exit chase. I think it is not easy to have both perfect entry and exit, and the bottom line is if you can DCA your entry and exit, it would reduce pressure on shoulders and can help you to invest and take profit more comfortably and effortlessly.