Because I honestly can’t. I can barely talk with the very few people I know. Is just so out of my range. That’s why I don’t have friends or a partner and I don’t see that changing.
EDIT: no, responding comments here or asking this question ISN’T having a conversation for me. So I don’t feel this as “progress”.
Yes I can. No I don’t do it often.
I have ADHD, and struggle to remember small details or infer the same things other people do from dialogue. This means that outside of structured discussions, I struggle to maintain a conversation that interests others most of the time. My friends are the ones who don’t make an issue of my shift between a lack of engagement or intense engagement and my completely forgetting things that other people things are extremely important like remembering names. I have had the same few friends for a couple decades because making new friends is fucking hard.
So when it comes to strangers, I tend to only have conversations a few times a year and almost always when traveling. Basically, if there is no chance of seeing them again and I have an easy out from the conversation I am comfortable starting one. Random people on public transport, in lines at restaurants, people at conferences, etc. Stick to whatever they bring up and try to keep up, consciously avoid dominating the conversation, etc. This all took a lot of practice over decades to become comfortable with and it takes a ton of work so I don’t do it often. The only reason I need to work at it is that most people think the things my brain doesn’t retain are important and that is generally what makes them think I’m not listening or participating. If I never see them again, then it isn’t important if I screw that up!
I am also an excellent presenter, and get tasked with that frequently. I don’t feel stressed in front of crowds because I practiced at it a lot and slowly became comfortable with it. For a lot of people social interaction takes practice and making ‘mistakes’ and learning that they need to adapt and not worry too much about whether the other person is enjoying the conversation, only if they give obvious signs they want to leave the conversation.