Is this circumvention of the GPL?

NOTE: I am entertaining these thoughts as a theoretical possibility and
am not going to do anything that I am describing.

1. Are you bound by your own GPL? Suppose that I write Foobar 1.0 and
release it under GPL. Then suppose that I make extensive changes to
it and release Foobar 2.0 but not under GPL. Would that be illegal? It
seems that the answer is no, since I am not bound by my own license.

2. Let's say that I write a program and release it under GPL. However,
the program is written in an extremely idiosyncratic style so as not to
be understandable to anyone but its author. Is it legal?

igor