I'm not open about my diagnosis due to shame. Most people don't understand what having BPD entitles and the ones that do have negative associations due to past experiences, so I tend to keep to myself and not explain to people unless absolutely necessary. 
But why is that?
I recently became close with a waitress at a restaurant close to my own (if you're in the industry in Pittsburgh, servers tend to befriend other servers) and when we went out for drinks last night it came out that she also had BPD, diagnosed five years ago. She listened to my concerns about my recent diagnosis, calmed my fears, gave me advice, and when I left I couldn't help but think the best of her even after hearing her horror stories. She texted me today to tell me she also thought I was a good person (which means a lot since I'm often called cold and unfeeling). 

I see a lot of the posts people write on here and I feel for all of those struggling. Just remember at the end of the day, we're not alone and we're not terrible people. Just a little misunderstood.