OK. I'll buy that.

Some years ago, I did some consulting and design work on a community condo pool at a luxury resort, and had to commute private plane, in a 1 1/2 hour flight. Several times, I was in a twin engine Beech, but mostly a single engine 4-seat Cessna, which may well have been a 172. On one return flight to Chattanooga, my pilot was threading his way along the NC/GA line between thunderstorms that were both south and north of us. I got into the co-pilot's seat with a fresh cup of coffee, before the pilot noticed. Once he did, he warned me to drink as much as possible before we got above 300 feet. I got a few sips before I had to cover it up with my hand. When we entered the downdraft across the primary mountain ridge, he was in a maximum throttle climb, and still losing 100 fps.

Needless to say, I didn't get another sip of coffee, till we landed in Chattanooga!