That might depend on how unmemorable you are. They serve 100s of customers a week. I know that cashiers and other associates have forgotten my face at times within just a few minutes. I went to a convenience store the other day for a shop and when I walked in, the cashier smiled and greeted me, asking how my day was going. I responded politely, we had a brief exchange, and then I went to check the restroom. I saw him again about 3 minutes later when I came to the counter with my purchases, and he gave me the same canned, "Hello. How is your day going?" No flicker of recognition that we had a conversation a few minutes earlier.
You might be able to go back a few weeks later, and it is quite possible you would get a different server, though I think that this particular MSC would have a rotation on this type of shop.