@georgetakei I think I know the part on knee surgery is not correct so I would like to see the source of both claims -
@erikoorthuijsen @georgetakei knee surgery regret of 6 - 30% is referenced in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961288/ (a Google search has various studies that mention numbers like 7%, 18% and 22% from a quick look at results)
Patients’ experiences of discontentment one year after total knee arthroplasty- a qualitative study

Total knee arthroplasty is a common procedure with generally good results. However, there are still patients who are dissatisfied without known explanation. Satisfaction and dissatisfaction have previously been captured by quantitative designs, but there ...

PubMed Central (PMC)