according to me idealism refers to the unrealistic belief in perfection or the unrealistic pursuit of perfection. now, when i say idealism is hard to achieve in real life i say so because the ideal image which is present in ones head in which he is in pursuit of is an everchanging image, an image which as no form or no boundaries.
when we as humans are constantly learning new things and grasping new concepts every moment then then how can the pursuers and the ideal image be a rigid thing.
ones ideal image is easily influenced by the likes and dislikes of the person hence the goal which one was targeting keeps on changing thus making it a difficult state to reach on.
one is not born with the concept of idealism or with an ideal image inside its head, rather it is fed to us by the society to always have an unrealistic goal or an image after which we keep chasing on.
I call idealism unrealistic because unlike ones dream which is a rigid goal which is achievable through dedication and constant efforts idealism is a boundaryless goal ever changing and ever evolving just as the person harboring this ideal image evolves.