I play in Chinese so I didn't know what is it in English, but you need to scroll down the "Friendly" interaction tab, usually in the end, a specific interaction to talk about dream.
I had been trying to complete this one too. The only option I ever got was "talk about dreams" (you have to be inspired to get that option). My mistake was that I invited the grocer over to the lot I was on, and even though his profile still said he was a grocer, the title after his name (when you mouse-over) was gone. I went to town and waited around until another grocer showed up, in the delivery uniform. It had the job title in red along with his name and I got the option to ask about his dreams as soon as I introduced my sim to him. It had the same little waving-guy icon that you get for other tasks.
