It sounds trivial and obvious, but are you reading error bars correctly?
Do you know whether you're looking at standard errors (measures of inferential uncertainty), standard deviations (measures of spread of individual observations), or 95% confidence intervals around the mean?
And are your intuitions correct about how to interpret each of these?
Here's a nice primer, refresher, or teaching article.
https://www.nature.com/articles/nmeth.2659
h/t @jakehofman
