Baffling

Yes, it certainly is. Seems strange that Lee had all those respected names around him yet would never 'engage' in a few sparring matches (excepting his own students), especially as he was so confident in his abilities. If he did spar I for one would have loved to see him him take on Lewis/Stone or Norris.
There was of course a story that Lee fought Ryan O'Neal (the actor) who was supposed to be a good boxer. I don't if it's true but Lee was supposed to have decked him with no problems. I suppose we'll never truly find out and just have to rely on testimonies, rumours and myths!