I think the idea is to recognize which side of the coin you naturally or subconsciously tend to fall on, and to consciously apply an asymmetrical or biased force to correct for that.

The author naturally struggles with pessimism, so his presentation and experiences are framed around forcibly developing more optimistic thought patterns. For the people you describe, perhaps the inverse should be applied (the same article from that perspective would be an interesting read!).

I would say that it's probably generally better for you (and those around you) to err on the side of optimism.