I was doing especially poorly in a Physical Chemistry lab class about 40 years ago. The prof was concerned about my basic understanding of a couple lab procedures and trouble in trying to write down the lengthy equation in the process.
Part of the unit we were studying had to do with the nuances between 'fermentation' and 'distilling' as regards to the Krebs cycle in the human gut, in the conversion process of digestion and energy storage in a chemical form.
A buddy had been brewing up homemade peach wine that wasn't half bad. I managed to parlay a bottle of that, through an intricate (observed) process with notes, temperature of liquids/gases etc, and build a still from which I produced A-grade peach brandy....so said the Prof.....but I knew it was 'Nearly White Lightening'.
And it WAS smooth. IIRC, it proofed about at something around 93% or so. In any case, it proved he had taught me enough to understand the process and pass the course....with 'flying colors'....HAR!!!
Cheers, gents.