The question is how to memorize that the first index of a matrix entry denotes the row, the second the column, and not vice versa.

I had come up with the crutch:
(1) Row fiRst, columN secoNd
and challenged the class to find something better: Here are the answers received:

(2) Row before Column -- as Summer before Autumn
(3) rows are Horizontal, columns are Vertical ==> H before V in the alphabet
(4) you must first row your boat, then proceed down the canal (column)
(5) fiRst acRoss --- secoNd dowN
(6) Rows Columns as in Roman Catholic: R before C