Some teachers at school stick out in your memory. One such was my biology teacher, Miss Taylor.
She would go off on long discussions about her own experiences, where it was relevant to the lesson. Once I remember during a sex ed class she told one of the kids, "Don't write this down, dear, your mother will have a heart attack".
Another time she said, "When the brain processes a stimulus continually, it becomes insensitised. For example, Gemma, can you feel your knicker-elastic?"
Lots of kids used to go to her for advice about contraception or menstruation: she was quite the Wise Woman of the school. When I was quite young I was building a barometer in science class. I was trying to make it with a balloon as the diaphragm, but Miss Taylor walked past as I was building it and said, "I don't think that will be sensitive enough... I think you should use a condom." The entire room stopped talking and stared at me. This was officially my second most embarrassing moment ever.
Once some kids brought in a bottle of whisky and shared it out between themselves at breaktime. She said, "Well, since I can't tell how much you each might have drunk, I'm afraid you're all going to hospital to have your stomachs pumped", and made it so.
Another time: "Surely you've heard of the principle of osmosis! 'Nicholas farts at the front of the class. Who smells it first and who smells it last?'"
Another time she was telling us about childbirth and explained, "It's like shitting a melon." The next lesson, she asked, "Did anyone prepare for this lesson?" "Yes, miss," said one of the boys, "I ate a melon". That same lesson she told us all to lie on the floor and put our legs up in "stirrups" (actually lab chairs). "Yes, come on, the boys as well." Then she walked around the classroom exhorting us to push.