Re: What was Data doing before the D?
Weren't Holodecks relatively new by the time the E-D was launched. If that's so then previous crews he worked with may not have had the experience in interacting with artificial people much less such a real honest to goodness android. That could have kept him isolated, physically and emotionally. His commanding officers may have had him, like Guinan said later in season two, "doing the dirty work." Once holodecks became commonplace, it might have become easier for people to interact with him.
Did I happen to mention, did I bother to disclose, this man we're seeking with a mole on his nose, I'm not sure of his clothes or anything else, except he's Chinese. A big clue by itself.
--David Addison, Moonlighting