I passed a ten year anniversary of a particular day yesterday, and I didn't realise it until today.
It might have been the first time I came out to someone, a psychologist who then sounded like she doubted me. This of course made me recloset myself to her, as I was an 18 year old baby bi in a bad place emotionally due to unrelated and related events (reason for a psychologist). She confirmed: 'I didn't think so, you're just immature'. I was devastated and the session went 30 minutes over. I never went back to her.
My mum noticed that I was very sad, and with some prompting I told her. But I wasn't ready for it and I closeted myself again.
Over the next few months and years I came out to people online and at uni and listened to bi podcasts and read about biphobia and stuff. It took two and a half more years for me to come out to my immediate family properly. And they are all great...