Jyotish is important because many times there are astrological reasons causing problems. We may feel like we are doing something wrong when something does not go our way, and this might cause us a lot of distress. For example, if you are starting a business and it is not a good astrological time you will face many obstacles. The same could be applied to health. You may eat correctly, do your best not to stress, rest, and generally take care of yourself, but not ever get healthy because more and more karma keeps coming up from the depths below. So its not that you are doing things incorrectly, its that more difficult circumstances keep arising but you need to maintain course. For example, I used to have fibromyaglia. This is very. very deeply rooted. I kept doing everything correctly and did not listen to other people. People kept saying that my vegetarian diet was causing my sickness, and why dont I just eat some meat! But really the astrology was not good. I was able to maintain and make slow progress forward during this period, but it was not until the astrological period changed that I improved. Since this dasa (time period) was ten years long, it would have been very helpful to have known all of this information from the start.
We need to know what the astrological weather report is so that we can navigate through these changes in life!