Guy Fawkes was sentenced to death and the form of the execution was one of the most horrific ever accomplished, he was hung, drawn and quartered. This was done to show the seriousness of the crime of treason.
The next year (1606) was the start of an annual tradition for the King and Parliament to give a speech to remember the event. Lancelot Andrewes delivered the first of many Gunpowder Plot speeches. This tradition, alongside the nursery rhyme, made sure that this crime would never be forgotten, hence the words "Remember, remember the 5th of November".
The poem is sometimes referred to as 'Please to remember the fifth of November'. The point in having this poem and remembered every year is to warn each new generation that treason will never be forgotten.
In England the 5th November mainly known as bonfire night, and is still remembered each year with fireworks and bonfires finishing with the burning of a Guy Fawkes doll. The dolls are made by children by stuffing old clothes with crumpled newspapers and other stuff to look like a man.
Here’s the full rhyme if you didn’t know it:
Remember remember the fifth of November
Gunpowder, treason and plot.
I see no reason why gunpowder, treason
Should ever be forgot...