Having to stop Bones from saving Edith Keeler in City on the Edge of Forever. Obsession. Or Kirk complaining how the responsibility of captaining the Enterprise sucks the life out of him, takes everything he has, etc, etc.

: I knew that the first time around.

It was more the why than the who.

: That sounds like the kind of thing that'll make you enjoy everything less,
: not just multiplayer. :/

True but you can't lose in campaign. :-) :-)