When you started using the Magic Keyboard, your fingers are likely to fall into the habit of trying to use these Windows commands:

• Home to go to beginning of the line (failed)
• End to go to the end of the line (failed)
• Ctrl + End to go to end of the document (failed)
  It’s going to the end of the document, not what I want.
• Ctrl + Home to go to the start of the document (failed)
  It’s going to the end of the document, not what I want.
• Shift + Ctrl + Home to select all to start of document (failed)

Some things did work — just not what you expect:

• Ctrl + Left to go to the start of the line (worked)
• Ctrl + Right to go to the end of the line (worked)

The solution

The only solution is to change my keyboard so I don’t have to change me.

1. Open Terminal in MacOS
2. Type the following commands, one per line:

cd ~/Library
mkdir KeyBindings
cd KeyBindings
nano DefaultKeyBinding.dict

3. Next, copy and paste the below key mapping into the editor that shows:

{
/* Remap Home / End keys */
/* Home Button*/
"\UF729" = "moveToBeginningOfLine:"; 
/* End Button */
"\UF72B" = "moveToEndOfLine:"; 
/* Shift + Home Button */
"$\UF729" = "moveToBeginningOfLineAndModifySelection:"; 
/* Shift + End Button */
"$\UF72B" = "moveToEndOfLineAndModifySelection:"; 
/* Ctrl + Home Button */
"^\UF729" = "moveToBeginningOfDocument:"; 
/* Ctrl + End Button */
"^\UF72B" = "moveToEndOfDocument:"; 
 /* Shift + Ctrl + Home Button */
"$^\UF729" = "moveToBeginningOfDocumentAndModifySelection:";
/* Shift + Ctrl + End Button*/
"$^\UF72B" = "moveToEndOfDocumentAndModifySelection:"; 
}

4. Then save the file by pressing Control ^ + o then Control ^ + x to exit.

5. Restart your Mac for the changes to take effect.