Learning by experience seems to stick the lesson in the mind. I recall finding out at an early age how the glowing end of a car’s cigar lighter could burn – and leave a circular patterned scar to prolong the lesson.
I also recall the hard lesson learnt about drinking too much as clearly as the time I discovered I should always wash my hands very, very, thoroughly after chopping chilli peppers before rubbing my eyes (or touching other sensitive body parts, come to that).