When you celebrate your achievement, you feel like a champion. When you try to do your best, you get the feeling of pride in your work and in yourself. That is much better than just trying to get by, because if you don't respect your work, no one else will either. Don't be afraid of failures. They are just set-backs that help you learn from your mistakes.
Science is supposed to be complex.
But the best thing to do is to make it simple. Take the complex and break it into simple pieces. Albert Einstein was one of the world's smartest people. But not too simple. Part of breaking things into simple parts is to be methodical.