His didn't say so, but his facial expression couldn't have spoken "Seriously?!" more clearly.

"I thought Moogles told this to all of the heroes," he said and he walked back around Luffy to face him from the front. "They call basic medicine for healing wounds 'potions' here. I'd assumed that since you enjoy adventuring and fighting so much, you'd carry one on you."

He regretted not buying any while shopping for supplies, but he decided to use his sparse savings to buy tools instead of medicine, since he planned on using the former. Besides, since Luffy was here longer, he should have known this by now, right?