I once missed a $39 flight to Denver because I underestimated the security line at DIA. It wasn’t even a holiday. It was a random Tuesday in October, and the line stretched past the baggage carousels, out the door, and basically into the Kansas border. I stood there, sweating in my puffer jacket, watching the minutes tick away while a guy in front of me tried to argue that his gallon-sized jar of local honey was a ‘liquid necessity.’ It wasn’t. I missed the flight, spent $400 on a last-minute replacement, and cried a little bit in a Terminal B…