Spooky return of all my data after re-install Debian

[opiedopy]

Question: How was it possible that all my files and programs reappeared after re-installation of Debian?
Background: After giving a Raspberry Pi to my grandson for Christmas, I worked with him to learn how to use it and Debian. Then, returning home, I resurrected and old Vaio laptop and replaced the old hard drive with a SSD and installed a fresh Debian Linux system on the laptop. I used the method suggested of a thumb drive with the Debian image on it for complete installation. After apt-get and other steps, I had a working Debian Linux laptop.
I agressively loaded the laptop with Linux programs and made many ill advised mistakes, especially loading and installing programs for "arm" machine because I learned that from the RPi4. But my laptop was x86-64 and not "arm" at all. I had some program problems.
So, I decided to start fresh, and re-install Debian for a clean Linux laptop. I choose Google Drive to save the multitude of files I had saved during my Python learning exercises, plus Libre writer many personal documents. I did the re-install of Debian from the thumb drive. It happened quickly and I was happy. It was a fresh laptop with none of my old files or added programs on it. I went back to google drive to get my files and the folder was empty! I had made a loading error to google drive and had not checked the drive after thinking I had transferred all my old files into it. So, all was lost.
I went to bed and the next morning turned on the Vaio laptop and VIOLA! Everything was returned to as-before the re-installation. All programs were installed, and all my 800 files in my document folder were there.
While happy, I decided to register in this forum and ask the question, How did this re-installation happen without my input or using a clone program beforehand???? Spooky or totally normal?
Thanks,
Happy in NC, USA.
Opie

[FreewheelinFrank]

Perhaps you elected to install the OS in a separate partition and the reinstall overwrote the system partition only leaving your data intact. Check how the disk is partitioned.

[opiedopy]

To: Freewheelinfrank,

It is a pleasure to have your quick response that was so helpful and accurate. There are indeed two partitions just as you predicted. I can't for the life of me remember that choice when I re-booted on the thumb drive, in fact I was so confused at the time it may have auto-booted. Perhaps Debian protects beginners like me from stupidity. If so, I am grateful.

Thanks,
Opie

https://www.binarytides.com/linux-comma ... artitions/

Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 532479 524288 256M c W95 FAT32 (LBA)
/dev/mmcblk0p2 532480 62333951 61801472 29.5G 83 Linux


Number Start End Size Type File system Flags
1 4194kB 273MB 268MB primary fat32 lba
2 273MB 31.9GB 31.6GB primary ext4

ooopppss! Frank, (and others reading this.) I happen to be on a visit and am on my grandson's RPi4 and NOT my laptop. I will power up the laptop in an hour or so and show you the partitions there as well. But, interesting, the RPi4 has two partitions. (More info later, but I am sure, Frank, you have nailed the question accurately.)

[sunrat]

Perhaps Debian protects beginners like me from stupidity.

Debian most definitely doesn't do that. It is more likely to reward stupidity with total destruction. You got lucky.

[opiedopy]

To: FreewheelinFrank and sunrat:

Here is my fdisk -l command on my Vaio laptop with 125 GB SSD. As described I initially did a boot-to-thumbdrive clean
Debian install, 64 bit to start this laptop, then did another boot-to-thumbdrive to start all over.
And now, I find three partitions! (ps - no..... after staring at data, it seems that I really only have 1 partition, /dev/sda. The other
partitions are very small. Same goes with the Raspberry Pi I showed earlier. Only one partition is of any size.)

Yes, I am lucky.

Thanks for your comments and help understanding this issue. I am a Linux believer.
I do believe that my question has been answered and think that this thread be open for similar questions
to my original one but partition-detail questions may be better served in a non Beginner Forum?
(ha, I sound like a pretend-Administrator. Sorry, but I get blasted for hijacking threads in my other forums on my other hobbies.)

Results of my Vaio laptop,
$ sudo fdisk -l
Disk /dev/sda: 111.8 GiB, 120034123776 bytes, 234441648 sectors
Disk model: FATTYDOVE SSD 12
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xfcefe26c

Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 232441855 232439808 110.9G 83 Linux
/dev/sda2 232443902 234440703 1996802 975M 5 Extended
/dev/sda5 232443904 234440703 1996800 975M 82 Linux swap / Solaris

sudo mount

/dev/sda1 on / type ext4 (rw,relatime,errors=remount-ro)