the Evil Line

Most published research findings are false:

Among the 45 most highly cited clinical research findings of the past 15 years, 99 percent of molecular research had subsequently been refuted. Epidemiology findings had been contradicted in four-fifths of the cases he looked at, and the usually robust outcomes of clinical trials had a refutation rate of one in four.

This is about biomedical research; I expect things are somewhat better, but not enormously better, in the mathematical fields.