I know that as the sample size increases, the sampling distribution of the mean will become normally distributed, even if the population data are skewed (non-normal). So we can safely assume that the sampling distribution of the mean will be fairly normal.
However, I was wondering what happens if the shape of the sampling distribution is somehow non-normal (it might be oblivious to us) and its associated SEM? Is the SEM going to be misleading for calculating the confidence intervals and significance testing?