No, you are putting yourself down, and I didn't explain myself properly.
You got 85% efficiency, i.e. 85% of what is theoretically possible.
That is a high efficiency, but not by any means impossible. The real question is can you repeat this for your next brew, and the one after that etc. If you can do this consistently, then you can adjust your grain bills to get the gravity you want.
There are only 10 types of people in this world. Those that understand binary, and those that don't.