I think young Spenser and The Boy would have been great friends.

In fact, when I was reading Chasing the Bear, I sort of forgot that it wasn't a Paulsen story, given, yes, that I have read so many Paulsen this month, but also because Robert B. Parker and Gary Paulsen seem to be men cut from the same cloth.  Men of honor.  That's what their writing suggests, anyway.  They might be, or have been, as in Parker's case, big weenies, but you won't convince me.
In any case, I can say for sure that if you like Paulsen, you will like Parker and vise versa.
This is a Young Spenser Novel, as it says on the cover, but I don't know if there are others.  No.  I just looked.  No more.  Who knows if there would have been though, as Parker died in 2011 and this was written in 2009.  It really is a retelling of some incidents in Spenser's teen years, as Spenser and Susan sit talking.  I love the dialogue, as always.  I've read all of Parker's stuff but this one and the one I am reading now, The Boxer and the Spy and Edenville Owls which I will certainly read as well.  I had forgotten about these titles and man, it is like finding money in the couch or in a pair of pants.  This treasure that was lost and now is found.  How I miss RBP.