Power
The power of nursing is a pretty cool thing: you help sick people feel better. In a lot of cases, though, your patients may be terminally ill (or just really old). In those cases, your power will be relegated to ensuring their final years are calm and comfortable. Additionally, there's a power struggle that you should be aware of: the famous (infamous?) nurse-doctor rivalry (source).
The struggle over who has authority and who can make decisions best for the patient is oh-so real. Just remember to keep your head and realize that you may need to concede more often than you want.