Trying to understand this text. "They leave happier then when they came in"

I don't know to what "leave" and "came in" imply here? Maybe to a workplace they worked in?

My name is Bob Farrell and I've been very fortunate to work a lifetime as something I love doing: serving customers. For me it was ice cream parlours, for you maybe it's retail, healthcare finance etc. Whatever we do, remember our business is not what we sell its who we serve. You and I are in the people business, we take care of people for a living, hopefully they leave happier then when they came in, at least that's what we try for.

Video (At 0:27)

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The speaker was the manager of a store that sold ice cream. When a customer came into the shop, he tried to serve the customer delicious, wonderful ice cream. When the customer took the ice cream and left the store, the customer was much happier.