Guy who changed my oil did something?

I have a 2011 Honda Civic LX, I went to the honda dealership where I got the car for a routine servicing: they did everything. I got the car back when I got home I noticed the part on the dashboard that tells me how many miles are on the car didn't have the milage, but it says "oil life 100%" how do I change it back so that I can see the mileage on the car? It's no big not I just like to know what my miles are, last I seen it was at 45,000

There's a black stick sticking out near that oil message. Touch that once and see if your regular screen returns. If not the directions are in the manual on how to get your screen back.

If the reset button on the dash does nothing, there's probably a button on the steering wheel that changes it. If you have a manual, it will explain all of that. There's more information in that info center than one really needs.

Read the owners manual in the glove compartment which will tell you how to navigate the odometer, fuel economy and oil USE monitor. Better yet take the car back to the Honda Dealer and ask the service managet to show you how