How to calculate the number of days between two dates?

I'm trying to calculate days between two dates. Let's say I have the date **'2005-05-25 06:04:08'** and I want to count how many days are there between that day and the current date. I tried doing:

SELECT DATE_PART('day', AGE(CURRENT_TIMESTAMP, '2005-05-25 06:04:08'::timestamp )) AS days;

But for some reason this returns 11, it's not taking into account the difference in years. How can I solve this?