Posted below for comparison reasons only are two commentaries that typify the interpretation of 11:23:
I would answer that those commentaries have a particular purpose to interpret it in such as way as to deny any sort of oral tradition, and in a sense deny the dual nature of Apostolic teaching: oral and written (2 Thess. 2:15); and I also found the rabbinical interpretation of 1 Cor. 11,23 to be interesting.
Even cross reference bibles generally take you to Gal 1:12 and 2 Cor 12:11 where Paul insists he did not recieve his info from any human agent but by revelation. ; ; Paul said he received it not from men but from the Lord, this seems a poor way to argue that what he is presenting is an established tradition that does not originate from himself and those who traveled with him. ; ;But I can see the matter is not as clear as ;anyone wishes.
Gal. 1:11-12: "Now I want you to know, brothers, that the gospel preached by me is not of human origin. For I did not receive it from a human being, nor was I taught it, but it came through a revelation of Jesus Christ."
First we should establish what "gospel" St. Paul is referring to. Gal. 1:16 would seem to indicate he is talking about his aural vision of Christ recorded in Acts: that Christ is the Lord and that he, St. Paul, was set aside to preach to the Gentiles. And the main difference between the verse in Gal. and 1 Cor. would be that Paul's claims a revelation from the Lord in Galatians whereas in 1 Cor. it was received from the Lord, and if you take the rabbinic formula theory, it would seem these are different things.
As for 2 Cor. 12:11, I can't really see much of significance there except for the fact that St. Paul is ranting... again.
I should like to rephrase my last statement, in order to exclude "belief" and make it more compatible with reason: Given the emphasis on right teaching and right belief in the apostolic epistles, it does not seem reasonable that St. Paul, a former Pharisee, would purposely take from a Greek mystery religion. It also does not seem very probable for St. Paul to claim that his statements at 1 Cor. 11,23 are from private revelation. St. Paul does claim private revelation for such things as his personal mission and the whole "Christ is the Lord, the Lord in heaven" thing, but he, assuming 1 Cor. 11,23 is not a private revelation, never claims historical information through private revelation. (I could be wrong here:) Early Christian mystics (sages, oracles, etc.) are never originators of unique historical information; it does not seem to be a part of the mystic charism of the Early Christian to know historical informtion through private revelation.Your last comment was a surprise to me, I generally avoid arguing with anyone who feels as you do, not because that necessarily makes them unreasonable, but simply because it's just not my style to attack religious conviction.