The Blind and the Clueless

When Greg first meets John Watson, he mentally wishes Sherlock the best. Lord knows that man needs someone who can keep up with him. When John keeps coming back, Greg is impressed. When they seem perfect for each other for each other, but neither of the blind idiots see it, well. Then Greg is less so.
aka 5 times Greg saw John was perfect for Sherlock but didn't say anything and one time he did.