My hair was stick straight when I was born. I had a lot on top and it was actually so straight that it would stick up and my mom had to put lil clips up there so she could 'tame' it
. I think my hair started to look 'wavy' when it grew out longer (maybe 2 yrs old?) but didn't actually get to be 3a texture and thick until I was about 4, before it just looked wavy.