I have been tackling a difficult problem. Two months ago, I came up a new idea for a famous problem. I didn't know whether the idea is valid or not. When I considered that, and I found the problem was not so easy that it could not be solved by the idea. However, I thought the problem turned to be clear by the idea. From that time, I have been tackling the problem. It repeated that I thought the problem was solved and found the thought was wrong.
I was considering the problem also today. The problem has not been solved yet, but I felt I go forward on the path solving the problem. It was stressful, but a lot of fun. I hope the problem was solved until the next month.
