When six people are trying to split a pizza, some stinginess appears. After all, more for one person is less for the other five.
But in interactions that lead to connection, to shared knowledge, to possibility, it's pretty clear that there isn't a zero-sum game being played. In fact, the more enthusiasm and optimism people bring to the interaction, the more there is for everyone else.
You don't need to save up the goodwill and encouragement you offer to others. It will be automatically replenished, and it pays dividends along the way.