(My evolving thoughts that extend from https://www.jetpen.com/blog/2010/06/20/currency-of-goodwill/)
The currency of life is life-energy. When we give things of value to someone to improve their well-being, whether it is material or intangible, we transfer life-energy from ourselves to the recipient. The esteem that we hold for others is counted in life-energy credits and debts registered in our personal accounting system. For strangers who we hold at arm’s length there is a direct conversion of life-energy into monetary units when we conduct transactions. Even then, the quality of such transactions is accounted for with non-monetary life-energy to account for goodwill that is earned or extinguished.