What do you mean by not seeing an old friend in spring and respecting the mountains and rivers and disrespecting the past?

This sentence mainly expresses an emotional experience and awe of nature during the journey. Specifically, we can understand that although we can see the beautiful scenery of spring on the trip, we can't share it with our old friends, so we keep awe of the landscape in front of us instead of indulging in the memories of the past.