I typed S in the URL bar, and it took me to petersons.com. Typed it again, and it came up with McDonald’s. Something tells me those 2 are passively jockeying for the top spot for the search. A quick re-Google (which initially showed McD’s as the first hit) shows that Peterson’s has, for the moment, taken the lead again.
I believe that search technique is spelled out in your “Quick Searches” folder in bookmarks. For sure the “goto abc def” will do a Google I’m Feeling Lucky search for “abc def”, and I’m not sure exactly what causes search terms typed with no first word. But maybe yours was deleted or overwritten.
I’ve created my own quick searches in Firefox, for example typing “map 1314 E Riverside St, Jackson, MS” does a search in Google Maps for that address.