Conversely, I find infinitessimals vague and woo-woo, especially the way physicists and statisticians often use them. Once the epsilon-delta style "clicked" fo

Conversely, I find infinitessimals vague and woo-woo, especially the way physicists and statisticians often use them. Once the epsilon-delta style "clicked" for me, it felt like second nature. How can you tell whether it's standard analysis that's confusing per se or you just had poor math teachers?