My DS's Special interests

I love my DS's enthusiasm about his special interests.  We can tap into almost anything if we use his current interests.  Here is a list of some of his interests over the years (he is 6 now):

trains

aeroplanes

elephants

satellites

spaceships

aerials

timezones

world cup 2010

flags

flight stats

Out of them all, aeroplanes has been the main theme.  I know so much about them as a result