More disc brake headaches

oldsmobile
alero

#1

looking for disc brake help. i logged on a couple days ago with the discussion title “disc brakes what’s going on” i found out today by looking closer to" all" the brakes-- they do not work on the inside. nothing shiny showing up??.i have no idea when they shut down? my brakes seemed fine to me until i got curious, backing up hearing a little scrap noise— then the rest of the day o.k. never has anything showed up on the abs warning system on the dash? the only thing i remember a month ago was putting my brakes on a snowy day and bumping into the curb at an angle? have no idea if that started it or not —again nothing on the dash to say something is wrong? and the braking system felt normal and it still does? any ideas what has happen i just want to be one up on my mechanic when i see him.he admires my details to the tee thanks to all you guys-- thanks for any help