girljulian We can't quote people who've already quoted someone else. No quoteceptions here.
I have similar difficulty figuring out the emotional difference between platonic and romantic.
I spent way too long doing the 'what if my blue is different to your blue' but with feelings, especially love. Took me a while to figure out that's fine just like my sight isn't the same as another person's even if I sometimes need help with it. I don't need to know if my feelings of love are the same sensory-wise as anothers.
I live with 2 other adults. One I have a romantic relationship with. The other is platonic (not affectionate at all). We've all lived together for a decade, all been welcomed at family events.
The difference for me is that the platonic one, I care and want him to have all he wants in the world, the companionship is there -- but I'm not drawn to him and am not drawn to be actively part of life in the same way. We've built a life together, but when he discusses his dreams, there is no automatic pull to be part of that, I'm contented for us to be as much as mutually desired. If he wanted to travel the world, my mind wouldn't automatically go to how I'd do it with him, I wouldn't challenge him on it unless I thought it was very reckless/dangerous/wildly out of character, I'd just listen and cheer him on.
With the romantic one, I care and want him to have all the things he wants in the world - and I'm drawn to be part of that and being part of making that happen together. When we discuss dreams and goals, it's automatic that we're talking about how we can support each other to do those things. I do challenge him more as I'm drawn to figure out his thinking.
However, this "aromantic" thing is nonsense. "Romance" describes various levels of friendship mixed with sexual attraction. There isn't some magical third feeling that is added on top of that to make "romance" and that's a very childish view of adult relationships that you could do with sorting out.
Maybe it is just a different level of friendship, but I don't think any model of emotions humans have is complete or definitive. While most are better at it than me, most research in this area suggests humans are generally not that great at identifying their emotions and what causes them as we'd like to think and that there are a lot more factors in our emotions that we're usually aware of. There are risks to getting too navel gazing about it, been there, but I don't think it's automatically attention seeking or childish -- philosophers and social scientists have been digging into the wide range of emotions and variations in how their experienced & considered since ancient times.
I mean, I had that emotional draw to my now-spouse when we lived thousands of miles away from each other before we ever saw each other just from his writing. They were nice words, but there was nowt sexual about it at that point. Emotions are more complicated than imagined in many philosophies.