go hard and fast
She also wrote in a fundraising campaign set for David online, "No more isolation from people or places, restrictions, living in hospitals; only swimming pools, going places, fun, playing with other kids, going hard and fast to make it count!
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I wonder how I have to understand this phrase "going hard and fast to make it count".
I've known that a "hard-and-fast" phrase is used as in "hard and fast rule", in which "hard and fast" means unchangeable for whatever reason and whatever situation.
In this article, what meaning does this "going hard and fast to make it count" convey, especially "hard and fast" part?
Could I rephrase it like this: I will do whatever to make it count with an unwavering heart.