It’s handy to see where the bookmarks are in a document but you don’t want to display them all the time. To switch them on and off do this:
File>Options>Advanced then scroll down to Show document content:

Tick or untick Show bookmarks
This all takes a bit of time so it’s better to have a macro so that you can switch display of bookmarks on or off with three clicks. If bookmarks are displayed, using the macro will turn them off. If bookmarks are not displayed, using the macro will turn them on.
Sub ToggleBookmarks()
ActiveWindow.View.ShowBookmarks = _
Not ActiveWindow.View.ShowBookmarks
End Sub