This is pretty heavy to take in. We never want things to end, whether it's our favorite show or our favorite food or a favorite song. Unfortunately, life is all about endings, for without endings, we would never really begin. But even if things end, it does not mean it is bad or over. In fact, it could very well be the start of something new.
The future is unpredictable. If you told me 10 years ago that I would go through everything I did, I would have called you crazy. If you told me 1 year ago that I would be best friends with the person I hated the most, I would have punched you in the face. If you told me 5 months ago that today would be the last day we talked, I would have just walked away. Things do not go the way we plan, which would make planning at all pointless. But we do it to generate a safety net or a fall back plan. How cynical of life, don't you think?
Now, I cannot think of an ending I have experienced that was ever NOT sad. After all, they are meant to be sad. But the sooner we understand that endings are a part of life and can sometimes be unpredictable, they become easier to withstand. Think of it like the common cold. It will always exist, and you don't know when you will get it, but instead of worrying and planning on when you actually do get it, you should just deal with it by taking medicine. Of course, you wouldn't be in close contact with people who have it, but even the best efforts won't always succeed.
The greatest things must come to an end. How else would we be able to look back and appreciate it? If something were forever, we would just toss it out and not focus much on it. Perhaps that is why we try so hard to live a happy life? We know it will end eventually so we want to make sure we have a blast before it happens. Do not let the end take you by surprise. If you see yourself nearing it, try your hardest until the very end, or at least try to end it on good terms. Life is complicated, and there is no room in your heart for resentment.