What would you/your group consider you to be an extrinsic source on? What would you be considered an intrinsic source on?

My group would come to me for all sorts of parenting ideas and thoughts, event planning, baking, and dancing. 

They might not know and be surprised I could also be a reliable source for nutrition and travel.

What is one stand-out example you can remember of a persuasive argument that you thought was credible at the time but you changed your mind? What made you change your mind?