To quote the always-applicable lyrics of R.E.M., “Don't let yourself go, 'cause everybody cries. Everybody hurrrrrrts sometimes.” OK, so everyone cries, but frequency can vary dramatically by age, culture, and sex. For example, the amount babies cry peaks at 6 weeks, drops off dramatically around age 2, and continues to decrease as they get older.
A comprehensive study that looked at emotional crying (the tear-jerking kind that happens when we're sad, in pain, or watching adorable videos of sloths) in adults across cultures found American women cry an average of 3.5 times per month, while men shed a tear an average of 1.9 times. Biologically speaking, we're still not sure exactly why we weep, but it's totally normal to have a monthly cry (or three).
(h/t Science of Us)