it is fun in low doses, had fantastic times on shrooms or LSD with friends. You can appreciate the world and small things like a little kid, gives you a different perspective on life. But i also had hard experiences, negative thoughts, fear etc. - in the end i learned more from those experiences than from the fun ones.
The government is afraid of it because you will realize that they are full of shit and our system of authority and obeying is absolutely ridiculous.