Answer:
Yes, "Life ain't been no crystal stair", is your metaphor
Explanation:
A metaphor is a figure of speech that makes an implicit, implied, or hidden comparison between two things that are unrelated, but which share some common characteristics. It compares two things without using the words "like", or "as".
The author uses this metaphor, as to say that life definetly hasn't been easy, and never will it be, but that's no excuse to quit or give up easily.
