I checked that link, and Google's profile of me is way off. Earth Sciences? Seriously? This is a comfort, since I figure letting the system run on bad information is just fine. It does suggest that Google isn't using some information it has on me. I'm sure it knows my birth year, but my browsing habits seem to suggest someone much younger. I must be 'immature.'
It put my inferred age as 65+ years old, when I'm 29. I'm not sure what to make of that, other than google is much worse at this than I thought they were ^^