There are some that do have regrets, some that do change back. Such occurrences are thankfully relatively rare as far as I know, and one can only feel sympathy for the individuals affected.
However as a personal thing I have now lived the last nearly 30 years as a female, 26 of them postop. I also lived partially as female for about 15 of the first 25 years of my life and I can honestly say that I have never had any such doubts.
I think one reason for this is that, unlike some, I made no effort to change my lifestyle and behaviour other than altering my physical body. Thus I did not seek to become some stereotypical "little woman" but merely a physically female version of the person I already was. Thus I gained the peace of mind I sought, but without sacrificing much that I had from my previous lifestyle.
I hope that helps to shed some light on at least one possible approach and answer.
And no the question is in no way offensive - the only time it would become offensive is if someone then tried to use the fact that some people do have regrets as a basis for arguing that because some had clearly made a mistake then others like me, who plainly did not, should be prevented from following their own life path. We all have to take responsibility for our own decisions on this.
Finally, because I know you come from a profoundly spiritual background, let me say that if there is a last judgement I will stand before my maker with head held high and I will thank him for the wonderful life adventure that he gave me in this. I am sure that, whatever others may think, he will not condemn me for doing something which has enriched my life. Does God make mistakes? No. But to some of us he grants the rare privilege of finding our own place on the gender spectrum.