I was thinking just this. A great example (again from Mr K) is on the second night I went out with him. He pointed at some girls near me and asked me what I thought of them. I said 'Nice'. He told me to go and tell them. I did, and they lapped it up.

Making comments that are more relevant to your thoughts at that time are more worthy. Else you could end up either overplaying it, or wonder why the conversation isn't going as well as the first time you said it... and then blame the opener!