Anecdotes are personal stories or accounts that are often used to illustrate or support a point of view or argument. They are usually based on individual experiences, observations, or opinions, and are not typically subjected to systematic investigation or verification. Anecdotes are not considered good evidence in science because they are subjective and can be influenced by biases and other factors. They are often based on a single, isolated event or observation, and cannot be generalized to a broader population or context. In scientific research, evidence is typically collected through systematic observation, measurement, and experimentation, and is subject to rigorous scrutiny and verification. Scientific evidence is based on objective and verifiable data, and is used to support or refute hypotheses and theories.

While anecdotes can be useful in some limited contexts, they are not considered reliable evidence in scientific research, as they can be influenced by a variety of factors, such as memory biases, selective reporting, and other sources of error. Instead, scientific research relies on objective and systematic methods to collect and analyze data, in order to ensure that the evidence is as reliable and accurate as possible.

Scientific evidence has a hierarchy and systematically assessed usuing various methods - The purpose of all this is to reduce the errors in our observations. 

“You must not fool yourself, and you are the easiest person to fool.” - Richard Feynman