Not only are some of the "standard" security questions bad because they're easy to research, some of them are bad because there are multiple correct ways to answer them, and it can be difficult to remember how you chose to answer.
My least favorite security question is "What street did you grow up on?" Depending on the answer to this question, there could be four completely valid ways to answer it. For example, I grew up on 5th Street. So depending on whether or not I feel like the word "street" ought to be included in the response, there are four correct ways to answer this question:
Now, I'll choose one today, when I provide my initial answer. But when I'm asked this question six months down the road, am I going to choose the same one? Maybe not.
The key is not just choosing good security questions that are hard to research and/or guess. They also should have unambiguous answers.