This concept of humility is all very well for other people, but it is difficult to implement personally.
Sometimes I wish that my sister and brother had not died (58 years ago). What if the first release of the polio vaccine had been without problems and my siblings had grown up ... and moved (respectively) to California and somewhere in the Boston-DC corridor ... and didn't much use email ... or come visit now that our parents are gone? Or what if David had been drafted and killed in Viet Nam? (Well, at least he could have helped me through high school; the student deferment would have been in place for him.) One of the nice things about wishing that things were different is that you can assume a particular best scenario as the only alternative -- best in the sense that it fits more neatly with your own preimagined idea of what the world ought to be like, and you don't always have to work out all the details of how the pleasant features that you imagine could all coexist without any unhappy ones being added.
The fact is that we don't know how to compare alternative life tracks, even to the extent that we are aware of the positive and negative features. If we could choose, we wouldn't have the skill to make a rational choice.
In all humility, perhaps it is better than we don't have the power to reverse and reset destiny.