Google behaving strangely

Today I found an interesting thing which i couldn't be able to analyze the reason.

Search for 'diffrent css for safari' on Google you can find this blog on the first SERP of Google.

The surprising thing is i ever before used the word "diffrent" through out my blog. Why it is showing this blog?

When i site search for the keyword of "diffrent" i am not able to find even a single word through out this blog(http://www.google.com/search?hl=en&q=%22diffrent%22+site%3Aweb-search-techniques.blogspot.com&aq=f&oq=&aqi=)

 It is quite surprising and interesting.