Congratulations! Sounds like you and DW have achieved a nice balance. Nice work!
I paid off the mortgage before I turned 40 so I understand the age/financial milestone thing. Good luck and keep on trucking!
I have a single credit card that I use for all medical expenses, (its not the HSA card). I save all medical bills each year, staple then together, and then put them in a box, along with the year end credit card reciept.