premise: Well , I had a lot of fun for my birthday , Lizzie and I started the evening at the Nitty Gritty , because on your 21st they give you a collectible mug and all the free beer you want . :D Unfortunately , the friend that I had invited along to go drinking with us did n't get back to me , so it was just her and I the whole night . I still had fun though , after we got done drinking at the gritty we headed to State St. and started walking in each bar that we saw , I managed to make it through four bars before we decided to start walking home . Who gave the writer a collectible mug and all the free beer they wanted ?
hypothesis: A bar on State St.