I still study math as regularly as I can because it seems almost criminal to let all that accumulated knowledge rot when I could conceivably attain an autodidact’s Ph.D.-equivalent basis of understanding simply by another decade and a half of continuous study. On top of that, I understand that the practice sharpens and enlivens me, and that continuous contact helps me to maintain a truth orientation and soundness in philosophical matters. Last, I need mathematical literacy in order to understand the things that seem to be most important to me, like the cosmological argument for the existence of God.
It’s highly unfortunate that I can only spare an hour or two here and there, but that’s modern life for you. And anyway, if the conjunction of ill-fortune and mathematics is under discussion, it would be inappropriate to lament anything other than the perverse institutional incentives that favor ISTJs from kindergarten to graduate school. These people have great discipline and memories, but no imaginations. This is thoroughly unsuitable for the art of mathematics, which contains many useful tangents and pitfalls.