Infectious kindness

I am very aware of my grumpiness, I find it hard to allow myself not to be effected by the daily grind and dissatisfaction that life can so easily offer. Seems strange for me to admit that, but hey, self awareness is important.
So, there was a program about grumpy old men, they complain about everything and to be honest I can relate. So when I go about my day I feel frustrated and then take it out on everything that goes past me in the day. The person who pulls out on me in their car, the other grumpy person who lets the door slam on you, its all just frustrating and tends to sit on me like a cloud of grumpy.
Additionally, something else I should say is I am a bit of an old soul, I feel we have lost a time in life were the simple things have been forgotten including generally our customer service and the day to day politeness, I am can often wonder where good customer service went.
This week though, I stopped at the services for a sandwich, the lady behind the counter looked impassive, neither happy or sad, I felt quite good and decided to make small talk with the lady who was serving me, we had a giggle about my ease at which I knew too easily what I was going to have, and then I noticed not only did I lift her spirits but then when she interacted with her colleague she too was also laughing.
It got me thinking, while it isn’t always true, what if we stopped expecting the world to smile at us first, if we are the ones to smile first then they will just follow suit. Kindness therefore is surely just an infectiousness that should be started somewhere, its up to each of us where. Food for thought, excuse the pun!