We may not have seen his encounter with the "future Federation" reminding him of the "temporal prime directive"
That said, can you remember your work mates from half of a life ago?
Human memory is good, but a life of adventure and an over abundance of scotch can give one "Swiss cheese memory" ala quantum leap
It's not even colleagues right? It's more like do you remember the faces of all the people that ever entered the office building you work in, you don't.
Explain yourself
I get the first part of the joke (klingons were on the Enterprise during the Tribble episode) but don't get the bit with O'Brian
In Deep Space 9 there's an episode called "Trials and Tribble-ations" where a number of the crew from DS9 go back in time and find themselves in the TOS episode "Trouble with Tribbles". The producers literally overlayed the DS9 cast onto TOS footage, and shot some new clips in the same setting, so canonically the DS9 crew was present for the events of the TOS episode (... at least as canonically as you can get when time travel is involved).
Warf and O'Brien were two of the DS9 crew involved in that episode, and they also happen to be on the Enterprise when Scotty is found trapped in a pattern buffer.
Wouldn't Scotty assume the Klingon in Tribbles and Tribulations was Worf's grandfather? If anything his reaction should be that Worf looks exactly like his grandfather.
