Lol. 😉 Don't worry. How's your tool situation? Got some hex drivers? Nut drivers ? You've got two bearings per wheel. Two on the differential, which is in the transmission, and several in the transmission. Those don't need service that often. But the wheel bearings, if you're in dusty conditions, yeah, every 20 battery packs you should check them for grit. Clean them if necessary, and relube them. 11x6mm bearings aren't cheap if you buy Bocas.