The real reason your flight is so uncomfortable

Experts say pain is a great motivator for upselling. Here is how to avoid the trap.

I’m still wondering how I ended up in seat 18E — a middle seat — on a Hong Kong Express flight from Phuket, Thailand, to Hong Kong. But it was an extreme inconvenience.

I was wedged in with just 28 inches of pitch between seats, which is about two inches less than normal. The plane smelled like mildew and body odor, and the seats looked threadbare. I tho…