A lot of people think they’re doing a lot better in the Google results than they really are. This is because Google uses something called ‘personalized search‘, whereby the results are customised to what it thinks would be more helpful to you. Now, we all know that someone in Japan is going to see different results from someone in the UK, but ‘personalized search’ means that someone at the next desk may see different results from you. Google is trying to take into account geography, topicality, preferences, patterns and even social factors in ordering your results. The real implications of each of these, none of us know.
You can turn off these results by adding &pws=0 to the end of the search url generated when you type something into Google. So, for example, http://www.google.co.uk/search?q=bmon should show you a personalised search for “BMON” whereas http://www.google.co.uk/search?q=bmon&pws=0 will show you a more generalised one, more likely to be a better representation of an “average” result.