"ALL" is implied by those who want to see the word "ALL" and get their shorts all bunched up!!! if the word "ALL" is used in the sentence, than that would identify "ALL THE YOUNG GUYS"
If you would prefer, I will use the actual name of the poster, then the sensitive people won't get offended.
Synonyms: apprenticed, benighted, birdbrained, blind to, cretinous, dense, green*, illiterate, imbecilic, in the dark, inexperienced, innocent, insensible, mindless, misinformed, moronic, naive, nescient, oblivious, obtuse, shallow, thick, unconscious, unconversant, uncultivated, uncultured, uneducated, unenlightened, uninformed, uninitiated, unintellectual, unknowledgeable, unlearned, unlettered, unmindful, unread, unschooled, unsuspecting, untaught, untrained, unwitting, witless
take your pick of words, my favorite would be moronic!!!