One thing that greatly helped this in the DOS / early Windows era was standardizing on F1 being the key for "online help" (meaning, usually, a hyperlinked docum

One thing that greatly helped this in the DOS / early Windows era was standardizing on F1 being the key for "online help" (meaning, usually, a hyperlinked document that shipped with the product). That was basically the only thing you had to know to start learning any app.