Is one of the planets really named Earth, or is that just a big myth?

Yup. It's in all the scientific papers and books and everything.

there are those who think so. huh?

Yes, yes it is. Though unlike the other planets' names, "Earth" is sometimes lower-case and used as less of a proper name for the planet and simply a word for the solid ground in general. It's much like "the Moon", where "moon" has become a generic term for large natural satellites. 

All a myth, we are just part of some higher beings dream and eventually it's going to wake up and "POOF" the Earth and everything on it will disappear.  

Earth is only used in the high language .... It's normally called Soil in the lingua franca ... or colloquially just dirt.