Given this sentence:
I find (content/contentment) when sitting on a crowded subway train.
or in the sentence fragment:
my place of (content/contentment)
In the dictionary, I see that content (as a noun) means "a state of satisfaction" and contentment means "a state of happiness and satisfaction". Therefore I am unsure of which one to use. Does the difference come down to formality or is there a proper use case for each one?