How to achieve immortality?

Probably so, but I think labraries are a little more circumspect about collections of “local-ana”.

My step-daughter was required to have her high-school thesis professionally bound in hard cover. I suggested that she ought to find a Wiki article that reaches the same conclusion, and add a footnote to her own work. That would survive for the life of Wiki, and would be a fun entry to her own CV. How many 18-year-olds have a Wiki reference to their work?

You can’t. Ok, let’s assume you become as famous as Alexander the Great or Jesus or the like. You’re being remembered, right? No, because social memory of those people is a complete distortion of what they really were. Even supposing our records of their accomplishments are accurate (they aren’t), we nevertheless don’t know them as people. They may as well be fictional characters.

Your third death isn’t when your name isn’t spoken for the last time. It’s when the last genuine memory of you is lost.

There is no sure way you WILL be found. I think the OP means assured that the data is there, to be discovered.

Yes.
The comical responses are appreciated, but this is essentially a serious question about how best to see that my memoir has a chance to be around as long as possible. I’m not serious about immortality, of course, but maybe I am about the possibility of not being utterly erased the moment I die, either. It’s pleasing to think "Well, maybe someone will come across it in 20 or 80 years and think “This isn’t bad. Interesting fucked-up complicated life. Huh. Who knew?” sort of thing.

I’ve had chapters of it published, btw, in various online journals that will go belly-up, I’m sure, in a year or ten. The credit always reads that this is an excerpt from a memoir, and I’d like it to be findable if anyone is intrigued by the online chapters. As I said, getting a memoir actually published is unlikely for a non-celebrity, so I’m looking for alternative methods as I collect rejection slips from publishers.

I know a bunch of people who have published memoirs using publication houses better than just print on demand but not as good as traditional publishing. You get on Amazon, but not in libraries.
For me, being published in archival journals is as close as I’m going to get, not counting having grandchildren.

My home town newspaper, a century-old weekly, had a write-up about my sister’s book concerning a relative’s correspondence during WWII. They’ve subsequently published additional excerpts. Since the newspaper is archived, at least in the local library, plus online, future generations could access these excerpts.

How long will the free cloud storage providers keep a customer’s data online? Assuming they don’t go out of business, do they keep the data forever or do they require you to log in occasionally to prevent deletion?

One thing that could work is to upload your memoir to all the free cloud storage providers, like Dropbox, Google Drive, etc. And then to make sure that people can always find your memoir, take out ads in major newspapers with the URLs to your uploaded memoir. Maybe use a QR code or something. The major papers of today will be archived in some form or another forever as long as humanity is around. Then if someone looks through the old paper, they may come across your ad with the link to your memoir and maybe they’ll download it and read through it.