I do not know if I would consider it underestimation.

[They're nearing the tea shop now, but his expression is genuinely thoughtful as he considers, going back through their many encounters. He has quite often persuaded her to do things, to accept his company, but that is far different from persuading someone to change— something he would never dream of.]

I am glad I have convinced you to tolerate my company on a number of occasions, but there are limits to even my efforts, genuine and well-meaning though they may be. I do not believe I can persuade you to change your point-of-view so completely, however, and I would not care to, for it is uniquely yours.