During early school-days I was taught that $2$-dimensional data points are described by $(a,b)$ where $a$ refers to the value of the $x$-axis and $b$ to the value of the $y$-axis.
Later I learned that matrices are mostly defined by $(m\times n)$ where $m$ refers to the number of rows and $n$ to the number of columns.
I am not sure if this is specific for me, but by starting to think from a two-dimensional area and then learning the notation for matrices always confused me, because of the reversed order.
Is there a reason for the kind of "reversed" order?