Well, personally, I don't think learning ANYTHING that's brand new is easy or a breeze. But it can certainly be done, no question.
I would agree with this. Saying learning [insert any skill here] is easy is, to me, a bit naive.
The other part of the question makes more sense to me. "Can anyone learn easily or special knowledge is required?" The answer here is yes, anyone can learn, and no special knowledge is required! Sure, if you can already play another instrument (and can mentally separate the right from the left hand motions, or are particularly dextrous), it'll make learning piano a bit easier. Still, just like anything, it will require a lot of time and dedication.
One thing I like about piano versus learning guitar is how linear the keyboard is. The octaves just repeat over and over - if you know one you know them all The fretboard on a guitar is a bit more confusing!
A piano is played by pressing the keys with the fingers of both hands. The standard piano of today has 88 keys, the three foot pedals also has specific functions. The pedal on the right is called a damper, stepping on this causes all the keys to vibrate or sustain