Whenever I do a post on some alternative medicine modality or practice like manifestation, someone will always contact me and insist it worked for them. And to them, this might indeed feel like strong evidence - but the reality is virtually never is, because they're not asking the right questions. Instead of asking whether something truly works, they're taking a known "success" and attributing it to the medicine or practice they believe in. But what we really should do is ask a deeper question: what about all the other cases? Survivorship bias is what transpires when we fail to ask that question, and it can cause us serious harm and lead us to wrong conclusions. Here's a brief post on why...