Yes, experience is a teacher. Time brings humility.
When I've done this------- I usually get some kind of repercussion in my life. I've ended up with some eye opening issue in my life that is very much like the person's that I am critical of . . . and then I have new empathy for them and feel contrite for my thoughts. It is like bad karma when I am overly critical of someone. It has brought negative things back to me. So, now I try to remind myself that we are all just people and unless you've lived their life----- you shouldn't comment about what they do right and wrong. (unless you are on the medhelp forums and they are asking for an opinion . . .lol) Show others the care and acceptance that I want. It could be me next time!