I booked a window seat for a six-hour flight because I experience motion sickness when I can’t see outside. I paid extra for seat 12A and boarded early so I could settle in before the plane filled up. A few minutes later, a man in his fifties stopped beside my row. “You’re in my seat,” he said firmly. I checked my boarding pass. “No, I’m in 12A. What seat do you have?” He showed me his ticket. 12B. I pointed to the middle seat beside me. “That’s your seat.” He stared at me in disbelief. “I need the window. I experience anxiety.” “I’m sorry to hear that, but I paid extra for this seat.” He laughed. “You’re about twenty years old. You can sit anywhere. I’ve been flying for thirty years.” I calmly repeated that I wasn’t moving. He leaned closer and lowered his voice. “Listen, kid. I’m not asking. I’m telling you.” A flight attendant approached after hearing the conversation. The man immediately explained that I was refusing to accommodate his needs. The attendant asked whether I would consider switching to the middle seat. I said, “If the airline offers me an equivalent window seat, I’ll consider it. But I’m not giving up the seat I purchased for a middle seat.” The man rolled his eyes. “Young people are so unreasonable these days.” I almost laughed. He was demanding that I give up something I had paid for because he believed his age made his request more important. The attendant checked the seating chart and confirmed that the window seat was assigned to me. The man finally sat in 12B, saying he intended to report the situation. Ten minutes later, he pressed the call button and requested to speak to the captain.