I left home at 16, I thought I felt adult then.
I got my first real job soon after. Which again I thought made me feel adult.
I moved abroad, alone when I was 18. Again, felt like an adult
But really, the only thing that has actually made me feel like an adult was having children.
But oddly, I still don't feel like I imagine an adult should feel in most areas of life tbh, if that makes sense? I like I feel like a 20 year old trapped in a 30 year olds body. My 'self' is still exactly the same as it was back then, just I know how to behave more like an adult now, so fake it