Why walking to the hospital without Kevin isn't fun for max

I had no such memories to cry over.

Explanation:

In Seedfolks, Kim takes up gardening to pay a tribute to her father whom she never met but knows that he had been a gardener in Vietnam.

Since, Kim has no memories of her father because he died before she was born, Kim cannot relate to her mother's crying.

Kim hopes, that although, her father had no memories of her, her gardening and hard work would somehow make her presence known to him.