You'll have to learn through the course of this friendship how to balance your own needs with those of your buddy. This could be a bumpy process but it's one that's important and instructive in the end. You may take on the more dominant role in this relationship, but if you exercise understanding and compassion, you can also help your friend become more assertive about expressing their own desires.
Of course, this could be a tricky issue; you're simply not as patient as they are, and your urges run stronger. But if you can exercise patience and compassion in dealing with them, you could really help them come out of their shell. You can learn from them, too. Their slower, more deliberate pace can help you learn to slow down and smell the flowers.