How do you take your water with you? I always forget to bring it

I have a shopping bag problem and a water bottle problem. I always have to buy bags because Im not a robot and I dont remember to bring them. I have 5 bottles and theyre always full, I never remember to bring my water bottle. I'm going to Spain tomorrow and I dont want to spend money on water/a plastic bottle but I cant remember to bring my bottle. What do you do