Okay, I’m probably not the best person to try explaining this, but I’m gonna give it my best. Keep in mind, there are different experiences and levels of aromanticism, much like asexuality. My feelings on it do not reflect the whole group. This is just me trying to explain it to the few friends of mine who don’t get it.
Basically, aromanticism is the complete inability to experience romantic attraction/feelings towards another person. It doesn’t mean we’re asexual (though a lot of us are, I am grey-ace myself) and it doesn’t mean we can’t date. It just means we experience dating differently. I, personally, don’t get butterflies or feel ‘lovey-dovey’ about other people, and it’s more like going out and having dinner with a friend when I DO date.
Some of us are actually really bothered by romantic conversations and situations. I.e., when a partner says something like 'I love you so much, you’re my entire world’, it might not go over that well, and will leave us feeling uncomfortable and, sometimes, scared.
A good way of explaining it, at least for me, is that I feel the same way about that stuff as a sex-repulsed asexual feels about sex. It’s just very uncomfortable and not something I want to experience because it is so far outside of what I want and can even feel. Not all aromantics feel this way, but some of us do. When someone says something like that to me, I get closed off and I feel extremely uneasy and sick to my stomach.
There is nothing I can do about this and I can’t be 'fixed’. I’ve been told by partners in the past that there’s something wrong with me and I’m 'damaged’, and that’s bullshit. If you ever say this to someone who is aromantic (or asexual) you need to go find the nearest trash can and climb in. And stay there. Because it’s one of the worst things you can do to someone like us. We already spend enough time trying to recover from thinking that about ourselves, we don’t need it from other people.
Aromantics aren’t that different from other people out there. We might not be capable of feeling the same way about our partners as other people do, but that doesn’t mean we don’t care. Platonic love isn’t weaker than romantic love. It’s just different. Just because we don’t say 'I love you’ a lot and don’t wax poetic about our feelings for you, it doesn’t mean we don’t feel anything.
A lot of aromantics don’t date, a lot of them do. All of us are different and it’s always good to know more about people and their individual needs. Always research things you’re not sure about, and be open to others’ feelings and comfort levels.