Have 67,000 on the truck. Did front brakes at 45,000ish and the rotors were fine. Have been wearing normally as far as I know for a while. Rotated the tires yesterday and noticed grooving or ridges in the front rotors and the backs are fine. Back pads are due, but rotors are fine. When I changed the front pads, I did nothing but pull the caliper off and swapped the pads. Pumped the brakes a few times and all has been good. Braking is fine currently. Pads are OEM.

Did I do something, or not do something I was supposed to? Do I need new rotors now or can I have these turned?

 

Grooves and waves are pretty normal. If they're not too deep, don't worry about it. As long as the rotor thickness is within specs, you're OK.