When and where shoud I go?

I joined the assembly a few days ago. The assembly required an application via the web, so I used the website to join. It was the first time using that site for me, and according to the page, the schedual for the assembly was:

- The Date: Sunday, February 22th, 2015
- The Time: 10:00am to 5:30pm
- The Place: Harajyuku Station Omotesando Exit
- The Description:
The parade would begin at 16:00.

It seems there is nothing wrong. But when I saw these information the first time, I misunderstood. I mean I was confused; 5:30pm and 15:30. So, I thought why this assembly will end before starting the parade? The parade will begin at 16:00 but this assembly will end at 15:30. Why? Will it be optional to go to the parade? I think people assume that they can't easily get out of their way thinking. It can be considered one of Murphy's laws, is that right? Anyway, the law applied to me. So, I understand what it meant. However, after calming myself, I've solved these questions on my own.

But, this story is not over yet. The same day, I arrived at the station and went to the exit. Then I saw that there were so many people, which reminded me. I had forgotten to write down a specific place to meet, and I couldn't search it because my mobile phone was dead. Where should I go? So, I looked around and managed to find the group, we were all heading to the same destination, which helped me find them. It reassured me so much. After that I enjoyed meeting and talking with new people.

The following are what I wanted to say.

1) I think when people assume something is true, then they can't easily get out of their way of thinking even though it's wrong. (In my case, I was confused; 5:30pm and 15:30.) It can be considered one of Murphy's laws, is that right?

2) The same day, I arrived at the station and went to the exit. Then what I saw was crowd. Additionaly, I realized I had forgotten to write down a specific place to meet, and I couldn't search it because my mobile phone was out of charge. So, I looked around and managed to find the group. I thought anyone might drop a hint that who have the same destination today. After few minutes, I found a likely group, and I was correct!