I had a friend who once told me that “Life is hard.  Once you accept that it becomes almost easy.”  As much as I love clichés and quotes, I know that when I’m stressed or struggling pithy sayings don’t do it for me.  I probably heard my friend say this and thought “whatever” or “Yeah, that’s real helpful.”
The thing is maybe people do get caught up in expecting it to always be smooth sailing.  Intellectually you know that everyone has trials and troubles but is there a small part that believes it should be mostly calm waters.  Maybe people think that there is a quota on struggling and once you meet that quota then things will be fine.   Like you may get to this land called HAPPY and the biggest concern you’ll face is if you need to stop at the store for milk on the way home.  It really doesn’t work like that though.  (Random sidenote –what possible wisdom would a person have if that was the extent of their concerns.)
Maybe the key is to accept that there will be obstacles – sometimes seemingly immoveable obstacles – in the way.  Having the obstacles does not mean happiness is lost.  It is not an all or nothing proposition.  It just is.  You can have a generally horrible, no good day with moments of happiness and conversely you can have a generally happy day with moments of trouble.
Work on changing your thoughts from “will anything ever go right for me?” or “what worse can happen” to “I can get through this”, “ I recognize the happy moments” and “this is worthwhile and I will be Ok.”

“Expect trouble as an inevitable part of life, and when it comes, hold your head high. Look it squarely in the eye, and say, “I will be bigger than you. You cannot defeat me” – Ann Landers