Why are multiple deer still called just deer ? and goose/geese?

Why are multiple deer still called just deer ? You have 1 dog, dogs. 1 cat, cat. 1 bear, bears. You can go on and on. Why are 2 or more deer called deer instead of deers ? And why are multple goose called geese insread of gooses ??Why are multiple deer still called just deer ? and goose/geese?
This is because the english language is frigging ridiculously complicated.Why are multiple deer still called just deer ? and goose/geese?
English has pulled in words from multiple languages and often follows the pluralization rules of the particular language (child, children). Of course, following this logic, the plural of deer should be ';deeren';.) Sometimes there are two ways to go. Hunters often use a singular form for the plural; the rest of us add ';s';. There is little logic. We say ';geese'; but ';mongooses';. BTW, ';Data'; is the plural form only; the singular is ';datum';.
That's just English. It's crazy, I know. All kinds of inconsistencies. English is well known for that, our ';claim to fame'; if you will. Oh well. Just gotta memorize it anyway.
Just few other examples:





Software - plural - software


Data - plural - data


And many other.





because it is English.
Just one of the joys of the English language.
Because you touch yourself at night.