“In love, women are professionals, men are amateurs”
The etymology and historical meaning of the term professional is, “from Middle English, from profes, adjective, having professed one’s vows, from Anglo-French, from Late Latin professus, from Latin, past participle of profitēri to profess, confess, from pro- before + fatēri to acknowledge; in other senses, from Latin professus, past participle”.
An amateur (French amateur “lover of”, from Old French and ultimately from Latin amatorem nom. amator, “lover”) is generally considered a person attached to a particular pursuit, study, or science in a non-professional or unpaid manner. Amateurs often have little or no formal training in their pursuits, and many are autodidacts (self-taught).