Gatsby had not used his swimming pool once untill the day he died. He was very wealthy and had access to many luxuries but did not enjoy them. The purpose of these luxuries was to impress his love Daisy. The fact that he used his pool before he died probably represents the fact that he knew his time was limited and he used this time to finaly induldge in the luxuries he had. He knew he would never be able to have Daisy now and so there was no point in just having things to have them. I hope that helps.