Believe repeated behavior before believing beautifully explained intentions.

Intentions are described and behaviour is observed, and only one of them has been tested. People generally mean what they say about how they want to treat you, and meaning it does not produce the capacity to do it. Repeated behaviour already accounts for their circumstances, their limitations, and their priorities under real conditions. That makes it far more predictive than any explanation.

When there is a gap between what someone says and what they do, take the behaviour as the forecast. This is not cynicism, since it applies equally to the good things people repeatedly do. Watch the pattern for a few months rather than the account of it.