Thoughts fill your head - but which of them can you be sure  are true?

a) The sun is shining.
b) It is very hot today.
c) You are very hungry
d) There are seagulls in the sky.
e) You have been shipwrecked
f) There are no other people on the Island.
g) The crown is made out of gold.
h) The crown is yours.
i) You are the ruler of the island

The sun feels very hot on your back. You seek the shade of a tree to think all these problems though. Something occurs to you. This might all be a dream. 

How would you know if it was ?

Worse still, the whole thing might be an illusion. What if someone is controlling it all,  playing some fantastic computer game in your head?

How would you know ?