It is generally thought that the left brain is digital, organised and systematic whilst the right brain is in charge of imagination and creativity.
Lots of my friends who have done this have been off-the-scale right brainers. Heads not just in the clouds but peaking through looking for new worlds to explore.
And as a musician, story-writer, ideas-generator, albeit as one who is fairly organised about such things, I expected to have at least a slight right brain bias too. Not the case. I came out as 60% left and 40% right - sufficiently left-brain dominant to be described as 'digital'.
It may be that I have changed. When in the company of the highly creative I tend to organise them; when in the company of the highly-organised I tend to generate ideas.
Every single one of these 'stupid' questionnaires takes me a step further to self-understanding.