A culture is like an immune system. It operates through the laws of systems, just like a body. If a body has an infection, the immune system deals with it. Similarly, a group enforces its norms, either actively or passively.
Dont use all-or-nothing thinking. Take each day as its own day, and dont worry about it if you mess up one day. The most important thing you can do is just get back up on the horse.
Everything has seasons, and we have to be able to recognize when something’s time has passed and be able to move into the next season. Everything that is alive requires pruning as well, which is a great metaphor for endings.
If you are building a culture where honest expectations are communicated and peer accountability is the norm, then the group will address poor performance and attitudes.