Saying "English is easy" is like saying "Tennis is easy." In playing tennis, beginners and professionals can seem to be doing the same. They are running on the square court, wielding the racket, and the rules of the game is basically simple to understand at a glance. Therefore the illusion that they both are playing the "same" tennis.

But can a beginner player win a professional player? Almost impossible. Does a beginner think he or she will reach within a year the same level of the professional? Most unlikely.

Contrastingly, advanced mathematics, for example, is visually and terminologically hard for laymen to even grasp what it roughly means. So one judges that it must be difficult. But a mathematician's career and a tennis player's career as professionals might be both same ten years.