The Start menu has definitely seen many changes over the years—from the traditional menu that was present from Windows XP to 7, to the Start screen in Windows 8, to the hybrid of the two in Windows 10. And while the return of the Start "menu" has received near-universal praise, there are still some aspects old Windows 7 users will miss. Namely, the User folder and content folders (like Documents, Downloads, Music, Pictures, and Videos).
The good news is that there is no mysterious elements involved here. Microsoft has simply decided to hide these folders by default from the Start menu. Luckily, bringing them back is a breeze once you know where to look.
Source:
How to Bring Back User & Content Folders to the Start Menu in Windows 10 « Windows Tips