Have gotten tired of being tracked by Google.
The first time I found out to what extent information is stored was when I checked the Ad Settings page of their service and saw their Compiled Profile of who I am as a Consumer, based on my Searches.
For the last year or so I've used DuckDuckGo; I have to admit, they weren't that good before but they are getting better in Results. Still, they don't understand Syntax and Contextual Searches as well as Google, so putting a question in a sentence doesn't work out as well as on Google.
So if I really do need to cast a wide net because I don't have an accurate way of expressing my Search then I'd go into Google, and clear out My Activity afterwards.