Do you agree with the line, “I’m only responsible for my actions, but I’m not responsible for people’s reactions”?

It’s a commonly repeated idea, particularly in Christian circles. The last time I heard it, it was phrased, “we should only measure the things we do, we shouldn’t measure the things other people do – because we can’t control it.”
So, first of all, yes. I am responsible for my actions. No amount of circumstances or “you made me do it” takes away from the fact that my decisions are mine, and I wear the responsibility for what I say and choose to do. Even if I didn’t mean to act that way–even if what I did was unintentional–I have to wear the responsibility for it.
Ok, what about the idea of being responsible for other people’s actions?
I think the best way to answer this is to say that we are “reasonably responsible” for other people’s actions. I do not believe this is a on/off idea, but rather a spectrum from “in no way responsible” to “significantly responsible” but never “100% responsible”.
If I do a bad job as a salesman, I’m partly responsible for you not buying the car. If I do a good job pitching and convincing you of the value of the car, then I am partly responsible for you buying it. I could do a terrible job selling it, and you might still buy it despite me–in which case there was probably some other factor partly responsible for your decision.
We ought be careful not to over-spiritualise Christian ministry away from this idea completely. If I do a bad job preaching, I’m both responsible for my words, and I’m partly responsible for the poor response it gets. If I do a good job, I’d be using the gifts provided by God as a good steward, and would be partly responsible for the results.
Isn’t this why Paul regarded the Thessalonians as his “reward”? They were the ones God used him to save, and Paul busted his gut to do it clearly and well. Not saved by Paul, but certainly saved through Paul’s actions to some extent.