He should not regret that thing at all, maybe yes at first but he should consider that as a lesson that he need to learn and need to take in mind so next time he can enjoy his bitcoin. Emotions can be deceiving we can get rich through excitement and get lose because of panic. Above all tips we should learn to manage our emotions because that is the big part of our decision. Take profit of you are already satisfied and happy, don't regret if it pumps more even, be contented a profit is a profit already.