Conflicting file versions (Git)

Can't push because behind - Case: 2023.10

On a beautiful autumn morning in 2023, we were greeted by a wonderful message:

$ git push
To https://github.com/acme/scripts.git
 ! [rejected]        main -> main (non-fast-forward)
error: failed to push some refs to 'https://github.com/scme/scripts.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

and git pull made sure there was no escape:

$ git pull
error: Your local changes to the following files would be overwritten by merge:
	src/update_all_dvb8.sh
Please commit your changes or stash them before you merge.
Aborting

Options:

Make a local copy of the site, pull and manually incorporate my updates in this file?
Check on GitHub for changes
Commit your changes: Commit, pull, and sort things out manually
Stash: 'Park' your own changes and proceed with pull

BTW, merge here means, that I want to include my changes in the current branch - To merge my files into the branch

Someone else changed a file as well - Case: 2023.12.04

Someone else made a change to a file and added one line
Made a local copy of the disputed file
Commit + pull
Git somehow solved it itself. I think the term recursive was mentioned somewhere?
Solved.

Impressive. Next time, do the same inlcuding making a local copy of the file before pulling.

Someone else changed a file as well - Case: 2024.06

The problem

I created file monitoring.sh
O. changed the file
I changed the file
I tried to sync and got

The solution

No idea how this happened, but when I checked some weeks later, both O.'s and my changes, were incorporated in the script.

Someone else changed a file as well - Case: 2024.07.02

This problem was similar the the problem I had a month earlier. It's even concerning the same file as last month.

Problem

$ git pull

remote: Enumerating objects: 11, done.
remote: Counting objects: 100% (11/11), done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 8 (delta 4), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (8/8), 2.19 KiB | 249.00 KiB/s, done.
From https://github.com/example.com/scripts
   020ac01..da7a0ae  main       -> origin/main
Updating 020ac01..da7a0ae
error: Your local changes to the following files would be overwritten by merge:
	src/monitoring.sh
Please commit your changes or stash them before you merge.
Aborting

Cause

O. and I, both changed file monitoring.sh before I committed my changes.

Additional information

See Git stash for some experimenting with git stash.

Approach

O. probably made only one minor and specific change, while I made tens of changes in this file. Hence I would prefer my version of the file to use as basis
I would prefer to resolve the issue manually. Just like old-school have two versions of the files alongside eachother
I'm not that versed in Git and I don't want to spend too much time on it. While trying and reversing git stash, I made backups of both versions of the files and now can open them side-by-side
When opening these files side-by-side, I discovered that the remote changes were already incorporated in the local file. They seem fine, but I find it worrying that changes are made so easily, and I only find them by compairing the files.