6gear myth in Accord Coupe

Myth, 6 gear on accord coupe. Was inform use only at higher mph. Or not neccessary, or when in use at the wrong sequence, rpm would drop. This all not true. For 6 month had been driving; hardly using the 6gear, oniy on the freeway at 80mph. Was on freeway, at 6o-65mph in 5gear without radio blasting, notice engine hitting the high note, until I shifted the 6gear. Hence 5gear at 45-55mpm and 6gear at 60-infinity. In racing higher rpm in each gear at which time, computer or tran, will alert you to shift.