Remember James Olson?
James Olson - IMDb
Hasn't been heard from for almost 30 years.
Or how about cult star Traci Lind?
Traci Lind - IMDb
Had her fun in the movies, married, and the last notation was in 2000. At least we know what happened to her but essentially, poof!
One would think with a familiar face, people would recognize one and it is hard to believe that all the people around one are so respectful of privacy that no one talks.
Of course, no one knew of Teresa Graves past until after she was dead.
Teresa Graves - IMDb
What does one need to do, leave the country?
After all, no one knew what happened to Aja
https://en.wikipedia.org/wiki/Aja_(actress)
until about 8 years after her demise.