I started playing by just picking up and copying what i heard and developed a pretty good ear.
Years later i decided to take things a wee bit more seriously and learn to read. (I was never given the opportunity to take up an instrument or do 'proper' music at school).
I found reading music and practising my sight reading very difficult.
Every time i got through a piece (were not talking anything major here btw) i would remember it, so next play through i wasn't sight reading it any more just playing from memory again. Now i know this is what musicians do all the time, when you know the dots your only really using the music to keep track of where you are but i really feel it was more difficult for me than it needed to be, reading a new piece straight from the music seemed to take me back twenty steps again.
My advice would be ...if you are serious, develop your ear but start learning to read early on, you don't have to be able to rattle out C minor prelude off the bat but it will be better for you later on in your career to have that basic grounding to build on.