Which line in this excerpt from Robert Frost’s “Mending Wall” suggests that the speaker and his neighbor are quite different?

There where it is we do not need the wall:
( He is all pine and I am apple orchard. )
My apple trees will never get across
And eat the cones under his pines, I tell him.
( He only says, "Good fences make good neighbours." )
Spring is the mischief in me, and I wonder If I could put a notion in his head:
( "Why do they make good neighbours? ) Isn't it
Where there are cows? But here there are no cows.
Before I built a wall I'd ask to know
( What I was walling in or walling out, )
And to whom I was like to give offence.
( Something there is that doesn't love a wall, )
That wants it down."