1) Looking back I have been gay since childhood. At the time I didn't even know what 'gay' meant, let alone identify as it.
2) Around 9-12 I understood what gay meant, but never considered that I was gay. Everyone (including me) assumed I liked girls and would eventually marry one. Even when having feelings for boys I just overlooked/ignored it and kept believing I would end up with a girl. Sounds like denial, but it wasn't even a conscious decision. I liked girls at the time, so I coudn't be gay. I just assumed (not 'tried to convince myself' - there's a difference) that it was 'a phase'. I think it had to do with society's general assumption that everyone is straight, unless proven otherwise. I was raised thinking that, so of course I assumed I was straight.
3) Eventually I came to realise that I like girls in an emotional sense (friends), but was not attracted to them physically. When I came to this conclusion, i realised that yes I am gay, came to terms with it, embraced it, and here I am today, happy.
Age 4: favoured female characters, but thought the male characters in movies were cute
Age 9-12: felt attractions (emotionally and physically) to male friends
Age 16: came to the realisation that I'm gay
Age 18: Accepted it, embraced it and came out
Now: Happier than ever.