Read this site: Setting Personal Boundaries - protecting self
and see how you can set healthy boundaries.
Not only does this enable you to see how allowing a 'second' or more chances can be allowed,OK in the grand scheme of things,and down right good for your learning coping skills/personal growth.
I had a friend who would not communicate well, as some will do from time to time.He crossed a boundary I had set with him, he knew this,he did it anyway(perhaps a test,perhaps because he didn't care,perhaps for some reason I still can't fathom)
Anyway,I let him know that,once again,this was unacceptable to me,if he choses to take the no communication route,(meaning,blow me off because he decided to not be responsible and call to cancel a meeting or be there when expected,etc.)I would not be around for this to occur.I have better things to do with my life than have expectations and meetings blown off for their whims and lack of responsibility.
In time,he reached out to find me apprehensive but willing,as long as he followed my boundary.
It isn't manipulation.
It isn't control,not in the sense most would think of it.
It is a clear line of ,"I'm not going to be treated like this because...,it makes me feel...,and this is the result you can expect if it continues..."
Much better description on the site quoted above.
Allowing someone a second or third or fourth, or a lifetime of chances.. isn't being a patsy,isn't being week,isn't being played,as long as we set a line of what we will accept as to their behaviors, let them know the outcome if things continue,and FOLLOW THROUGH with our boundary and set line,, things will progress without us being guilty and questioning ourselves(much like what this post is about)
I hope this helps:)