Men aren't from Mars

and women aren't from Venus but there are many significant differences.

The male hormone androgen that is associated with facial and body hair is a key factor in hair loss and dandruff / flaky, itchy scalp. One of the main reasons men suffer most from these complaints. Stress is also a contributor to flaky, itchy scalp. 1 out of every 3 men use an anti-dandruff or medicated shampoo at least once a week (twice as many as women).

Most men shave daily, damaging and/or removing up to 2 layers of skin. Who says men don't need a moisturiser?
Men's skin tends to be oilier than women's due to larger sebaceous glands.
Men's skin is prone to infection after shaving, including shaving rash.
Men sweat most and travel more as a result of work.
Men with a full head of hair have finer and approximately 10% more scalp hairs than women.
Men generally wear their hair shorter and use more styling gels and wax as well as tending to like different fragrances to women.
Men keep their toiletry/beauty products in a limited space environment such as the shower or bathroom.