Changing gears manually is you paying a lot of attention to speed and direction. Once the first part of getting comfortable changing gears is past, you as the driver change gears based on paying attention to engine noise, speed, driving conditions, other vehicles.
You end up paying a lot more attention to everything, vs being largely on autopilot with automatic transmission. Or at least having the option of being a lot more on auto pilot with auto transmission.
Of course this varies driver to driver, but having driven both types for about 10 years, I personally find mysel way more engaged with the manual vehicles.
