Grammatical gender rarely matches biological sex
Even in languages with grammatical gender, the category assigned to a noun is often arbitrary and has no logical connection to biological sex or any inherent property of the object -- German's neuter "Madchen" (girl) is a well-known example. Treating grammatical gender as a pure classification system, rather than expecting it to make intuitive sense, makes it far easier to accept.
Not every language fits neatly into "has it" or "doesn't"
Beyond the two- and three-gender systems common in European languages, some languages (like several Bantu languages in Africa) sort nouns into far more categories based on shape, animacy, or other features, while others drop gender from nouns but keep it in pronouns, as English does. Grammatical gender exists on a spectrum rather than a strict yes-or-no divide.
Frequently Asked Questions
If I get the gender wrong, will I not be understood at all?
In most cases the meaning still comes through, though the sentence will sound noticeably off or clearly incorrect to a native speaker. In a small number of cases, a noun's meaning actually changes depending on its gender, so it is worth learning the correct gender carefully rather than treating it as a minor detail.
Does English really have no grammatical gender at all?
English lost grammatical gender almost entirely at the level of nouns, articles, and adjectives, but traces remain in customary usages -- like referring to a ship as "she" -- and in third-person singular pronouns like he and she.