If the plural of man is always called men,
Why shouldn’t the plural of pan be called pen?
If I speak of my foot and show you my feet,
And I give you a boot, would a pair be called beet?
If one is a tooth and a whole set are teeth,
Why shouldn’t the plural of booth be called beeth?
Full version of Ode to Plurals
This and the former example should finally prove wrong the wide spread assumption that English is an easy language.