# Confusion in understanding the derivation of wave speed from Newton's Second Law

In the book 'Principles of Physics' by Resnick,Halliday and Jearl Walker,the opening para of derivation of wave speed from Newton's Second Law is such:

Let us consider a symmetrical pulse moving from left to right along a string of speed $v$. For convenience,we choose a reference frame in which the pulse remains stationary;i.e,we run along the pulse,keeping it constantly in view.In this frame,the string appears to move past us,from right to left with speed $v$

My confusion is :

If I am moving with the pulse,I should moving left to right with velocity $v$ wrt the reference for which pulse is moving left to right with velocity $v$.

So I should have zero speed wrt pulse and string both.

How can the string be moving right to left with speed $v$ if I am stationary to the pulse?

Are not the velocity of the pulse and velocity of the string are in the same direction and of same magnitude?