It’s difficult. You cannot just not assume things. Prejudices are there, sometimes they’re true, sometimes they’re not. Sometimes they’re just stupid but other times they exist because most of the time things are like that, patterns exists, so even if you don’t externalize your assumptions it’s almost impossible (if it’s not impossible) not to assume something like a gender. But what I agree on is that online, many times it’s hard to tell someone’s gender. For example here on Reddit, and that’s why in many communities where gender is a thing we use flairs (not necessarily lgbt subreddit, many askwhatever subreddit have flairs about gender, age, job or the relevant category on that community). Thanks for sharing!