Student or Learner
Then, of course, there are some memories that need to be left behind. The memories of past hurts, unforgiveness, bitterness, and anger should be left behind forever. These are the things that we should never keep until the next time, mail back, or bring with us to our next visit.
What does the underlined sentence mean?
Thanks for your help!
As an NES but not a teacher, my reading of what it means is:
If you've had problems with someone, don't "bottle it up" inside you, waiting, maybe, for a chance of revenge (?) when you next meet.
If you do, the person you are likely to hurt/damage most is yourself!
Hope this helps.