ArcGIS Pro was first released in January 2015. If you dove-in head first, you may have used ArcGIS Pro for up to four years.
I was a little later to the game and dove in during the big push during the release of ArcGIS Pro 2.0 (Summer 2017). Personally, I am beginning to be more comfortable with Pro for certain workflows, but still find myself reverting back to ArcMap often to complete tasks more efficiently. I still use ArcMap more than ArcGIS Pro.
What about you?