A limit, boundary, or edge can have many meanings, depending on the context. Some possible meanings include:
An extreme or something "far out" (such as "the edge of the world," "the edge of reason," or "the limit of my patience")
The best, the most, or other superlative concepts
Personal limitations, or perhaps some way in which you are limiting yourself in your life
Limitations put on you by others, society, circumstance, environment, or something else outside yourself
A challenge or obstacle in your life