How long does it take to choose a name?

How long did it take you guys to choose your new name?

I'm trying out my third name now. I keep going through a pattern of finding a name, liking it, using it for a few weeks to months, and then out of nowhere I'll go off it. Like after using it and liking it for a while I'll just suddenly not like it anymore. I can't tell if this is because I realise the name just doesn't suit me, or if it's because it's just not my birth name which I've been used to hearing for 20 years.