A. Instead of shooting down the teachers' old-fashioned views, why not ask them how they managed to potty train children at 18 months? Maybe you'll hear a useful tip.
My guess is that you'll also hear of toddlers who were not so much toilet trained as they were toilet trainers -- they'd taught their moms to anticipate their urges and get them to the bathroom on time. I sure learned my lesson the day I ignored Madeline's protests, and she pulled off her diaper and left a nice little deposit on the Play-Doh factory tray.
Keep in mind that most child-rearing philosophies are subject to revision. Now it's in fashion to toilet train much later -- a trend that probably took off with the advent of those super-absorbent disposable diapers, which make it easier to live with an incontinent person for three years.
When you toilet train has nothing to do with how good a mother you are, and you should try not to take the teachers' comments so personally. Instead, consider responding to their success stories with an all-purpose "That's so interesting," and let them know you realize that changing diapers all day is a lot of work.