Maybe he was. The headpiece obviously means something, but it could be either his crown as king of Egypt (after he defeats Ra), or the symbol of his godhood after awakening as a god
Wait, the first flashback of chap 153 shows he already had that headpiece while he was carrying out his experiments with humans before the second flashack, in which he finally went to challenge and defeat Ra... Also, "bald Osiris" still posed as a foreigner in Hermopolis, where he was already able to use his godly powers as God of Life to "harvest the lives/kill" all the humans in Hermopolis at the same time, so...
Im such an idiot i thought Osiris already was a god. Also if you can see the past cant tou just look at your own if tou lose your memories?