Really confused, Who taught Obi Wan

Well I see your point, but all I'm saying is that Yoda instructed all Jedi, Obi-wan told Luke that Yoda instructed him.

There is a complete series on this whole subject its in the EU series of Jedi Apprentice.

Obi-wan gets trained by yoda and then QG goes to the jedi temple to pick a padawanand at first QG dosent accept him as an apprentice and Obi goes of to a planet to work on a farm (because he turned 13 and could no longer train) but then by chance QG meets up with him and needs his help and in the end Obi becomes QG' apprentice

thats just what i read in the EU books so if u dont believe in them dont bother listening

He just didn't feel the need to explain to Luke all of his past. It was irrelevant to Luke he was trained by QG, and Yoda sort've teachs all the Jedi youngling or not.