Free Printable! Ask the same 20 questions year after year (1-18, but probably age 3 or 4 is a great age to start) and see how your child's responses change year to year. Makes a great keepsake to give to them when they turn 18.
Birthday interview questions ask your kids these questions every year on their birthday once they can understand them and see what they say and how it changes. I'm going to do this and record each year.