Finished my 500th slab on Tuesday and the number caught me off guard

I was writing up the invoice for a garage pour in Fresno and the job number on my sheet read 500. Sat there in the truck for a minute doing the math because it did not feel like that many. Started tracking every pour in a cheap notebook back in 2019 after I lost track of a punch list and almost ate a callback on a driveway in Clovis. The weird part is nothing about Tuesday felt different, same 4 inch slump, same 8 yard truck, same sore back at 3pm. Somewhere in that notebook are two full tear-outs I had to eat and one slab I still drive past and cringe at. What surprised me is the notebook is the only reason I even know the number, so if you are not writing your pours down, what are you doing to keep track of yours?