If your toolbar, including the bookmarks bar, suddenly disappears in Chrome, it might be due to an accidentally enabled full-screen mode. Press F11 on your keyboard to exit full-screen. If this doesn’t resolve the issue, right-click the top of the Chrome window to check if the option to show the bookmarks bar is disabled, and enable it if necessary. Additionally, navigating to Chrome's settings under 'Appearance' can provide an option to toggle the bookmarks bar on or off.