Albert Einstein quoted "Reality is merely an illusion, albeit a very persistent one". Hinduism preaches "Jagat (Universe) is Maya".
I agree some of us have understood that material world is an illusion because the material is perishable and cannot be owned forever by anybody.
Let me share my views. The matter which appears to be felt by our senses is made up of Energy. Our eyes cannot see formless Energy but can see Matter (made up of Energy). This shows Matter is an illusion/ Maya for our senses and formless Energy is the reality. Thus, this Material Universe is illusion/ Maya. We All have to accept Everything is Energy and Information. Yahoo! ;)
This post is dedicated to Albert Einstein because it was inspired by his quote. Feel free to correct me, if I am wrong, but not Einstein.