Could someone explicate and explain this poem for me?

It is called the History Teacher by Billy Collins



The History Teacher - Billy Collins

Trying to protect his students' innocence

he told them the Ice Age was really just

the Chilly Age, a period of a million years

when everyone had to wear sweaters.



And the Stone Age became the Gravel Age,

named after the long driveways of the time.



The Spanish Inquisition was nothing more

than an outbreak of questions such as

"How far is it from here to Madrid?"

"What do you call the matador's hat?"



The War of the Roses took place in a garden,

and the Enola Gay dropped one tiny atom on Japan.



The children would leave his classroom

for the playground to torment the weak

and the smart,

mussing up their hair and breaking their glasses,



while he gathered up his notes and walked home

past flower beds and white picket fences,

wondering if they would believe that soldiers

in the Boer War told long, rambling stories

designed to make the enemy nod off.

Could someone explicate and explain this poem for me?
The history teacher has appointed himself as a judge of what should be taught as history and so censors the information he teaches according to his judgement.



His judgement appears to be that the next generation should know nothing of any of the extremes that have happened to humankind. The poem does not given his reason for thinking thus, but it does give examples of how he censors history to fit in with his judgement.



Like Mr. Rogers, he puts on a sweater and speaks softly of the ice age and never tells the students the reality that human kind was almost wiped out to extinction. That might lead to questions of how humankind spread over the different continents which may lead to controversy so he insulates the students from the bitter cold of the ice age.



But the next hurdle to come for our history teacher is the stone age. Again he judges that it is better to meander around any controversy about human kind's origins as surely must come up in a discussion of why there were cave people when the great religions do not mention them.



And speaking of religions, perhaps oor history teacher is a Catholic for a great many people were tortured and killed in the name of Catholicism and the Catholic's self-appointed speaker for God on earth, the Pope. So the Spanish Inquistion is glossed over.



The War of the Roses recieves the same treatment as well as the most horrific thing man can do to man - atomic warfare.



The students learn nothing of how to deal with their differences by historical examples because of the censoring history teacher and so they fight on the playground.



As the history teacher walks home he contemplates how to censor the next class about the Boer War and the reader of the poem is left to wonder if the teacher realized the disservice he is doing to his students and ultimately humankind?



Those who don't learn history are doomed to repeat it. (Santayana)
Reply:As is the case with many of Collins works, it comes to its dark side before it ends. It ends up that The History Teacher does not protect the children at all. His children run out of the classroom like a pack of wild animals...they run out to the playground to hurt and tease as many of the other children as they possibly can.
Reply:It's a clever indictment of political correctness.