Lies I tell myself / Beth Vrabel.

Enhanced descriptions from Syndetics:

In this "heartfelt, emotionally insightful" ( Kirkus Reviews ), and funny companion to the acclaimed To Tell You the Truth , Raymond has a life-changing summer when he's sent to Maine to stay with the grandparents he's never met.

Raymond has always preferred to keep life simple and leave adventuring to other people. But then he's sent across the country, against his will, to spend the summer before fifth grade with grandparents who think he's "troubled" and needs to have playdates set up for him. Determined to show everyone how brave, confident, and un troubled he can be, Raymond hatches a three-step plan:

1) Learn to ride a bike. His mom never got around to teaching him before she left.
2) Learn how to swim.
3) Make friends. On his own.

But can Raymond really change, or is this whole plan just a bunch of lies he's telling himself? With the help of his great-grandfather's old journal, a feral chicken, and a possibly imaginary new friend, Raymond might just overcome his fears and figure out who he really wants to be.