Re: may be the old man is not madara??
C'mon guys.The picture clearly shows the young Obito Uchiha being medical treated by an old man with a 3 Tomoe Sharingan and hair that looks like Madaras.Who could it be?
The Sage died so long before even the 5 Villages were created!This is Madara taking care and saving Obito's life!
My opinion is that after the accident,and Madara having survived with his battle with Tobirama Senju,and now,being very old,he started training Obito and also do the thing he knew doing the best; brainwashing members of the Uchiha Clan.
I believe that Obito's sensei was Uchiha Madara,that later on,obviously died,and Obito wanted to continue his masters legacy and "plan".