When computer displays switched to WYSIWYG (which stands for “What You See Is What You Get” and is pronounced wiz-ee-wig) all those characters disappeared. It was great on the eyes but not so great for making changes.
When you aren’t sure why your text looks the way it does, your first action should be to make these symbols visible. On the Home ribbon, in the top right of the Paragraph section, hover your mouse over the paragraph proofreader mark, “¶”.
The command is called “Show/Hide.” Click it. In The Voyage of the Dawn Treader by C.S. Lewis, Lucy has to recite a spell, “To Make Hidden Things Visible.” Think of the “¶” as this spell.