My parents have been married for a long time. Over the years I have noticed signs of them not getting on, which me and my sibling would talk about this in private. Recently my mum apparently told my sibling that she and my dad recently had a conversation which they agreed they were not suitable for each other but they will stay married as it is easier. I know I haven't actually heard it from them but my sibling would not lie. When I heard this it has affected me badly, I always knew deep down they had some issues but it is the fact they even know themselves. I'm quite a sensitive person so she would not tell me this. I just can't understand how people can go from starting married life to travelling, pursuing their goals and raising a family to becoming depressed, having mood swings and gaining weight. I know I cannot be held responsible for anyone's happiness and it is not my issue to deal with. I just feel sad that they are unhappy. My friend had the same happen with her parents and she was really upset at the time. I just wish I could go back to being oblivious to not knowing this information. Should I just ignore it and get on with my own life?