That's nice of you to say, thanks.Oh, my, I would so love to meet you.

In a semi-related theme, back when I worked at a hotel front desk, I used to make a game out of making grumpy people smile. It made for a much more happy experience all around.
These days, I tend to make a point of smiling and greeting people I encounter in passing or at the mailbox or similar situations. No special reason, it's just that so few people do that anymore. The mailman at my complex was a particular challenge. He'd diligently avoid noticing anybody so I always made a point of giving him a cheery greeting. Little by little, at least with me, he progressed from grunts of acknowledgement to returning the greeting and yesterday was a particular victory. He noticed me from across the parking lot and waved to me before I did to him.
Jan