Keith got badly injured after fighting Galra soldiers, and since the Castle didn't have enough energy for the Cryo pod, the pilot had to be put under strong painkillers.

You stayed by his side just to make sure that his state wouldn't worsen, witnessing the alien pills having a weird affect on him.

"Last night I dreamt I was a bottle of ketchup and you were mustard, which is weird because usually you're mayonnaise in my dreams," He mumbled with a goofy grin. "What do you think could it mean?"