to struggle with stumbling or plunging movements (usually followed by about, along, on, through, etc.): He saw the child floundering about in the water. to struggle clumsily or helplessly: He floundered helplessly on the first day of his new job.
Because when brian had woken up and was thirsty it reminded him of a time him and terry we're lost in the woods which brought up the thought of a nostalgia memory