2) Complaining is easy - Trusting God is a learned behaviour.

It is quite human to complain about our lack or present circumstances. Even though we say with our mouths that we are trusting God. The thought processes that can rage in our minds, are really powerful, and if we allow it, our thoughts will take us in the opposite direction that God intends for us. It takes an ongoing effort to learn how to "cast all our care on Him"

Even though we are exhorted to "forget the things that are behind us" it is hard if we allow a negative thought to loop endlessly in our heads. God says "forget" because He knows that no matter how badly we mess things up, His ability to "make a way in the wilderness" and "rivers in the desert" (Isa 43:18) is not hindered by our ability to mess with His blessing. Nothing is too hard for the Lord and "All things are possible". He has laid a table before us in the presence of our enemies. He anoints our heads (mind and thoughts) with oil so that our cup runs over and goodness and mercy follow us ALL the days of our life.

1) God has answers to life's surprises

God is so good and His mercies are new every morning. When life dishes up things that take us by surprise, He has made ready and keeps ready the things that we need to walk in victory and blessing. All we have to do is trust Him and let His "peace that passes all understanding" fill us. That means, we don't need to know how He "always causes us to triumph"

One of my favorite scriptures "What eye has not seen and ear has not heard and has not entered into the heart of man, [all that] God has prepared (made and keeps ready) for those who love Him [ who hold Him in affectionate reverence, promptly obeying Him and gratefully recognizing the benefits He has bestowed]. 1 Cor. 2:9 (Amplified)