My advice to anyone always is: Be kind. Treat people how you wish to be treated. This beautiful artwork also goes further than that and it's true, we are all dealing with something in life. I always try to come from that angle if someone is complaining that people are unreasonable. It's never easy to put yourself in someone else's shoes, you have no idea what that person is dealing with.
I had an incident at work fairly recently when someone pointed out that I never smile and they took it personally. I do but it's quite rare at the moment because to be honest I am literally just trying to get through each day at work because I am usually in so much pain :( so although I never told that person what I have just typed, it just hurt my feelings that they made it about them... So yes that is my advice just be nice to people, even if they don't 'earn it'.