Most times you don’t have all the facts and data at your disposal. You can’t prepare 100 % for every moment and event. You have to go with your gut instinct.
I learned about a race a week before. I had not prepared that much but I had often ran in the past several months. In an ideal situation, I would have known about the race, prepared for it enough and be ready on race day. I knew that I did not have enough time to properly train for this race but my instincts had told me that I should register and go for it. I did register and participated in a 5k run. I was able to maintain a good pace and complete the race in a good time.