Just remember before you pass judgment that there are people out there who find your level of education and what you believe to be stupid and they may very well believe you have shit for brains.

Also considering that they have done well enough to put a roof over your head I would say they must have learned something that worked well for them in life. Light speed isn't something that effects our every day lives and even today it is not a main focus of the schools.

Your parents must be nice people if they are still giving you a home despite your age and the fact that you hate them and have no respect for them.

Try to remember these things in future and maybe you will not get as angry.