Also, how much the light is bouncing around, depends on the materials. A lot of non-metals absorb quite a lot of the light that hits them (depending on the material, the color and the angle the light hits the surface, ‘dead on’ reflects only about 4% of the light, with non-metals) so after a few bounces, there is relatively little light contribution left.
So, if you cover your walls with shiny paint and your bed and pillow sheets out of silk and the bed frame out of chrome, you’d get a lot more light bouncing through the scene. But even then, where the sunlight first hits a surface ‘dead on’, will be the brightest.
