I assumed they meant the first of the remaining members.
Given Mick's heart, Bill's predilection for jailbait, and Keith's relationship with booze, cigs, and falling out of trees ; Charlie seemed like a safe bet as last man standing.
(OK, we all know that Keith is going to still be thriving, after the cockroaches have deemed the planet uninhabitable).
Charlie was the oldest, of course, by 2 or 3 years and was a pretty established player before he took up with those young punks.