Same here. The old vBulletin / PHPbb format felt positively archaic once I got over the shock of how different the basic interactions are.
I can understand some hesitance from people who are naturally wary of infinite scrolling, as the vast majority of implementations are terrible. Where Discourse succeeds, though, is in managing state such that it doesn't feel brittle when you're deep into a thread's history. The developers built an infinite scroll that has feature parity with classic pagination, plus the far better UI of a "timeline" scrollbar.
I can understand some hesitance from people who are naturally wary of infinite scrolling, as the vast majority of implementations are terrible. Where Discourse succeeds, though, is in managing state such that it doesn't feel brittle when you're deep into a thread's history. The developers built an infinite scroll that has feature parity with classic pagination, plus the far better UI of a "timeline" scrollbar.