Perhaps when the person or people behind Satoshi Nakamoto invented a decentralized monetary technology, he or they envisioned the invention to be used for day to day stuff like groceries. So far, the invention which is bitcoin looks successful and promising in the future, however it is not as easy you might think for bitcoin to simply put the current fiat monetary system old and obsolete. As a matter of fact, bitcoin is still fighting a great battle for its place under the sun. However, due to its features such as absolute anonymity for transactions, it became a great mode of payment underground. But it's not what it is made for, I believe. When the time comes for bitcoin and its use to be as ubiquitous as a particular fiat currency then perhaps grocery stores would accept bitcoin as payment. We're going there definitely. Help spread the good news which is bitcoin.