I found my way to a new (for me) blog, Corresponding Fractions, which has a sensible answer to the what keeps me blogging question. Over to you, Ralph and Daniel:
This [blog] is my Savings Bank. I grow richer because I have somewhere to deposit my earnings; and fractions are worth more to me because corresponding fractions are waiting here that shall be made integers by their addition.
—Emerson, Journal (1834)
You must collect things for reasons you don’t yet understand.
—Daniel J. Boorstin