Hope is a great falsifier. Let good judgment keep her in check.

Wanting something distorts the estimate. Hope edits the evidence quietly, upgrading maybes into probablys and treating an absence of bad news as good news, and it does this while feeling exactly like clear thinking. That is why optimistic forecasts are so consistently wrong in one direction.

The remedy is not pessimism, which distorts just as reliably. Write down in advance what you expect to happen and by when, then check it against what did. Hope is worth keeping as fuel and worth excluding from the part where you estimate.