For people that have used the TeX macro language for a long time and have great comfort with it I think it is difficult to grasp how difficult that language is

For people that have used the TeX macro language for a long time and have great comfort with it I think it is difficult to grasp how difficult that language is to learn/use even for someone fluent in many other languages. The difficulty of using the TeX macro language is even greater if you have the misfortune of needing to use it, wait several months, repeat.