I started searching (tangibly) when I was 11.....going thru my parents lock box late at night, when they were asleep and I could "sneak" the key from it's hiding place.
I dug thru everything I could lay my hands on, trying to find some shread of something that would give me information. I spent my teen years "eaves dropping" and trying to get as much information as I could.
I joined organizations when I was 18, and out of the house at college.
I applied for my non-id info as soon as such an option existed in my state.....
And I hired a state appointed intermediary at 38 -- the minute I knew that option existed.
But to answer your question in a more "intagible" manner....I searched every day, in my heart, from the day I knew what adoption meant.....which was about three or four years of age.
Hugs,
Sally