I ask because as one podcaster put it at that time "you pretty much can find a Jedi by looking under a rock." So in what sense does Yoda mean that since there where other Jedi hanging around?
As per the two opposing answers found in At the start of A New Hope are Yoda and Obi-Wan really the last remaining Jedi?, it's true from a certain point of view. While there were members of the former Jedi Order still alive, still Light Side users, the Order itself was essentially shattered. The council itself had been slaughtered except for Yoda. One way to look at it was that Yoda and Luke themselves were no longer Jedi, merely Light Side users. The other is that Yoda was the sole remaining member of the establishment and therefore the only one left who could grant Luke membership, creating a continuity of leadership.