That's because Guinness doesn't travel well. If you want to REALLY taste true Guinness, go to Ireland, where the foam on a tap-drawn glass is thick and creamy enough to draw a Happy Face on, and it has enough vits/minerals to replace a full meal! It's the waters of the Liffy that does it, so I'm told (though if you stand on the O'Connell St. Bridge over the Liffy in Dublin, the smell of the water might cause you to never drink Guinness again, LOL).
BTW, as a music lover, you might remember Paddy Guinness was instrumental in hosting The U2 concert at Leixlip Castle back in 1979 or 1980 I think it was, followed by one by the Boomtown Rats who were banned from performing in Dublin.
Newly