Bo Jackson: 'I Don't Know Who Brock Lesnar Is'

Bo don't know Brock ... apparently.

With Brock Lesnar referring to himself as "the modern day Bo Jackson" -- due to his UFC and WWE success -- we went right to the 2-sport authority and asked Bo himself how he felt about the comparison.

Bo -- who was at Eric Dickerson's charity golf tournament -- told us straight up, "I don't even know who Brock Lesnar is, man."