Why did the gas go to therapy? Because its pressure and temperature were changing, but it just couldn't find the volume to speak up about its feelings.
One scenario could be heating a gas-filled balloon with a constant volume using a hairdryer, where the temperature of the gas increases causing an increase in pressure but the volume remains constant. Another scenario could be placing a gas-filled syringe in a refrigerator, causing the temperature of the gas to decrease and the pressure to decrease while the volume stays the same.
One scenario could be placing a balloon filled with gas in a room and heating the room, which increases the temperature and the pressure inside the balloon, without changing its volume. Another scenario could be reducing the volume of a gas-filled container while simultaneously decreasing the temperature, resulting in a decrease in pressure while keeping the volume constant.