When I was approaching the end of my private pilot training, my flight instructor heard something that he thought "sounded funny" while performing a steep turn on a training flight. We made a quick precautionary landing at an airport away from our home base. We got out and inspected the airplane. On top of all of this, my instructor was running late. He had to get back home so his wife could go to work.
As we hopped back in the airplane, my instructor took the controls to start the plane and perform the run-up and mag checks. When I would do this, I would meticulously run through every item on the checklist, and double and triple check things. When he started the plane, I had never seen anyone run through everything so quickly. He did the mag checks as we were taxing while doing some partial breaking to keep us from building up too much speed. This was an un-towered field, and there was another airplane that he wanted to "beat" to the runway so we could depart first. As we rolled onto the runway, he "let" me take the flight controls and fly the plane back to the home base.
After landing back at the home base airport, and as we were putting the airplane away, I commented that I was glad to see how "real pilots" fly once they get their licenses. He was not too happy with that comment and let me know that I should never do anything like that.
Do as I say... not as I do...