I grew up in a religious home and was always pretty religious myself. In college i ended up leaving the church and religon entirely. I think the last straw was that there are so many mutually exclusive religions, but only one or none can be right, so how did all the "wrong" ones form? Turns out humans are very good at creating religions and cults, and it's way more likely that my religion is no different.

Leaving the church set me on a path of having to actually think about ethics rather than just going by "whatever the bible says", but besides not going to church on sundays my life didn't change a whole lot. But in thinking about ethics the only thing that seemed to be able to solidly root ethics was pleasure/pain, or more broadly wellbeing/needless suffering, not an in-the-moment stereotypical hedonistic view of it but broader, factoring in long term results and the impact on others.

That was fine for a while, until an argument with my dad where he pointed out "if that's what you base ethics on, why don't you include animals in it" and at first i was like yeah obviously kicking a puppy is wrong and that's captured by my view, but it got me to think deeper about it and my actions and i realized that all sentient beings are morally relevant, and i could no longer eat them for my own pleasure. After that i also learned fish are sentient and that the dairy and egg industry are very cruel too, and i couldn't support them either, and i went vegan.

Now my perspective is more refined, i would describe my ethical views most succinctly as sentientism, an antispeciesist extension/improvement on humanism