Why? Oh why?!?

Those of you that have toddlers already know how is like to be asked “Why” all the time. However, today Is the first time I experienced it! My daughter is 3 years old but until now she never really ask WHY so many times.
This morning as we were preparing to leave for nursery we had this conversation(in English because even though my 1st language is Romanian my daughters is English and whatever I will do she will still answer in English):
Mummy – come on sweetheart its time to go to nursery
Boogie – go to nursery? Why?
M – Because you like it there and because mummy and daddy need to go to work.
B- ok…but why?
At this point I was a bit puzzled but I remembered what my parents use to tell me…
M – Because we need money sweetheart
B – Money? Why do we need money mummy?
M – Ah…well..we need money to buy food, clothes and toys for our little boogie
B – Ok mummy I like toys…can we buy more toys?
M – Yes we will buy now we have to go to nursery…
B – Why??