My ex killed herself. Being suicidal was actually one of the things we bonded over initially. I was more passively suicidal back then and she more actively, so when the topic came up it was almost always from her. It wasn't at all a taboo topic and she wasn't the type of person to hold back from expressing herself. I think that even despite understanding the suicidal mindset myself, I tried to fool myself about the situation and was less helpful and empathetic than I could or should have been. I think most people will try to "stay positive" and blind themselves to the severity of the situation for as long as possible. Reality is often just too much to deal with.