A nice contrarian view to positive thinking, Oliver Burkeman’s The Antidote: Happiness for People Who Can’t Stand Positive Thinking. A nice short (under 3 minute video), good quote below:
There’s a wonderful Stoic technique called “the premeditation of evils”, which involves deliberately visualising the worst-case scenario, instead of the best one. One benefit of that is that you replace limitless panic and fear – which is how we often respond to problems – with a sober analysis of exactly how badly things could go wrong. The answer might still be “really bad” – but not infinitely bad, as the Stoic-influenced psychotherapist Albert Ellis would say. That’s something I put into practice every day, and find helpful.
I am not sure whether negative thinking, what was and is my worst-case scenario (debilitating chronic condition with poor quality of life), helped me or not, but I certainly did contemplate it.