I haven't been a musician for 20 years. At least, that's when the only marginally serious band I was in called it a day. While I recorded in 2006, that was a one-off and I was swiftly back to never playing as my services were no longer required.
Despite this, I did keep a bit of a grasp of music theory from studying it up to grade 4 (but only to enable me to work towards grade 8 drums). The limits of this understanding were exposed today when I tried and failed to count the time signature of Keep it Greasy by Frank Zappa. I don't even know how to count 19/16 and 21/16, even while knowing what I'm supposed to be counting.
Vinnie Colaiuta was in his early 20s when he played on that track. There really are levels to this game.