Fame have you honestly never seen an act of generosity/kindness that wasn't motivated by some kind of transactional thinking?
If so, that I think you must wander around with your eyes closed because I see them all the time:
The people who leave the supermarket and quietly add a bag to the food bank/dogs home trolley.
The person who helps lift a buggy up some stairs/on and off a train.
The people who donate clothes to charity shops they could have ebayed.
All the millions of volunteers in Brownies/Cubs etc etc who give their time (and often money other resources for free)
Volunteer Firemen/Policeman
Food bank/playscheme/charity workers
Have you never seen anyone give coffee and sandwiches to a homeless person?
Have you never seen people stop to help someone injured or broken down?
The random Mum in the park who helps with spare wipes/nappy/plaster/snack
From a personal point of view, I didn't keep well at all during my pregnancy and random strangers helped me out several times:
Unknown teenagers carried my shopping to the car (more than once, different kids)
a stranger bought me some water and chocolate when I fainted in a shop
Strangers checked on me when I was throwing up in loos/the side of the road/hedges etc etc etc
The final month I was on bedrest- unknown to me a group of older ladies in my church, all neighbours who didn't know me very well organised a secret rota to pop in and check on me several times a week. I only worked it out later on. I could never work out how to repay that kindness, until about two years later when we had about 4 feet of snow. I snuck out and secretly dug and salted paths for them and cleared a walk way to the main road.
They didn't visit me for thanks or praise they just did it to cheer me up and check I was ok.
I didn't dig their paths for thanks or praise I just did it because I was grateful and it would make their day easier.
I bet if you looked around you, really looked you'd see stuff like this everywhere. You should try it, try participating in it. It will make you smile and the world look brighter.