Why does Duolingo require me to strengthen so many skills daily? I have completed the Spanish tree, and I had to strengthen 30+ skills today alone. I simply do not have the time to do so, and they look ugly when they are not golden.
This is a common problem and a common question. Duo is trying to help you by getting you to revise so language gets into your long term memory. You will need some patience. If you strengthen or finish a lot of lessons in one day later they might all decay together. Take it easy. Be patient. If you work steadily, eventually your tree will settle down. This post has some very good explanations and tips. https://www.duolingo.com/comment/6176795