You and I are very busy people. Timing when to jump in can be difficult if you don't know the local rhythms and rules. An example is a seminar class where Akiko kept waiting for a silence to make her contribution. Conversation is fundamentally interactive, interpersonal. It requires response.
Conversational patterns are highly structured and very difficult to shift.
Even when you speak another language well, you'll probably use your native language conversation strategies. Sakamoto describes American conversation as a tennis or volley ball match. You have to choose to go after the ball and hit it. Someone else may get there first. You have to respond to the last hit.