Ford had an argument with Arnold: Are the hosts gaining consciousness?
Arnold said yes!
Ford said no!
Arnold dies. Ford suffers because he loved Arnold. So somehow that convinces Ford that Arnold was right all along.
Why does that convince him? Who the hell knows. They don't explain. Perhaps the suffering that Ford felt led him to feel more conscious, so he assumes that the hosts can also become more conscious by suffering? I dunno.
Anyways, so Ford is convinced. But he doesn't want anyone to know that he is convinced, because everyone knows that Arnold and Ford had a big disagreement, right? And Ford wants everyone to think that he still disagrees with Arnold, right? He really needs to cover this all up, right? Umm no. No one even knows Arnold's name or appearance, let alone any disagreements he may have had with Ford once upon a time.
Seems like he was only trying to hide it from us, the audience.