There is no technical reason why a person could not always have been clear, though it is somewhat unlikely.
-snip-
How is a "technical reason" different from an ordinary walkin'-around-scratchin' reason?
"Tech" means Scientology tech, and if someone - prior to 1978 - walked into a Scientology Org and said, "I'm a Natural Clear!", he would have been regarded as a nut.
Similarly, if someone had walked in to an Org in 1965 and said that he was infested with other beings who had been implanted 75 million years ago by a galactic despot named Xenu, he would have classified as "PTS type 3."
The history of Scientology is the history of Scientologists adapting to the latest Hubbard "fact."
After the Dianetic Clear announcement in 1978, there were tape playings of a 1950s lecture where Hubbard talked about making Clears in 1947. Almost instantaneously, hundreds, if not thousands, of people, became convinced that they were past life Clears, having been audited by Ron in 1947.
C/Ses in Missions, and in some Orgs - still having not adapted to the new official reality - were hesitant to "validate" the state of past life (mostly 1947) Clear, and not too thrilled with the the giddy crowds of "Dianetic Clears" either. (Having examined a lot of PC folders from this period, I could see why.)
But Hubbard had decided that he wanted more Clears. Period.
So he said the Clears were "there," and presto! they were "there."
What attracted me to Scientology initially - when I was a naive panty-waisted dilettante - was the idea that Scientology offered a means to "dehypnotize" a person. Turns out that a very limited (some) amount of "de-hypnotizing" takes place but, if one hangs around, the "re-hypnotizing" begins.
No thanks.