Star Trek: Voyager1995

Neelix:
Seven... when you were a Borg, you were involved in some... unpleasant activities.

Seven of Nine:
I helped to assimilate millions.

Neelix:
I don't mean to be insensitive; but... do you ever feel shame... about what you did?

Seven of Nine:
Frequently.

Neelix:
How do you manage to keep going, knowing that you've done such horrible things?

Seven of Nine:
I have no choice.

Neelix:
Guilt is irrelevant?

Seven of Nine:
On the contrary. My feelings of remorse help me remember what I did, and prevent me from taking similar actions in the future. Guilt can be a difficult but useful emotion.