Activation of a book "Practical Statistics" and "Essential Statistics".

This book, gives plenty of exercises. From basic to complex sums. I had spent 3 sessions, to get the first "Ahaa". I will be doing some more time.

Basically in finance and costing field, statistics is quite essential. Not to have extreme knowledge, but just knowing the formula can be okay. During my activation of the aforementioned fields, I had urge to understand statistics. I rationalized for some while, then finally went and picked up the book.

First session, I just did s superreading. I found what had interested me, and what was relevant to me.

Second Session, Built questions on the based of curiosity, and did some practical sums.
Third Sessions, same as the second one.

The "Ahaa".
While waiting, in a queue. I was given a number. Current number on the screen called, and between my number, had 90 numbers. It wasn't a quite place, many people, and more people pouring in. As this place where I was, in a secluded place, I had to call-up a friend to pick me up. My friend would take 20 minutes to reach, he was little busy so couldn't make him wait here. The job would take 5 minutes. So to best way, not to waste my time would be to call him, just 15 minutes before my number, so by the time I get free, he is there to receive me.

As I was looking at the called numbers, and the time it took them to call another number. For some reason I found some consistency, with that, I got reminded of the statistic problem, which I had read. The problem was similar, the time it took to serve bunch of customers, what would be an average waiting time, and standard deviation of waiting time.

So I noticed that around 10 numbers were called it took around 7 minutes later, Another 10. 3 minutes later another 10. 10 minutes later 7, so on. So I had probability or long interval and short interval. I knew an average of 10 numbers were called.

With that, I just knew instantly how much waiting time I had. So to say, my prediction was accurate. If I had not read that sum, I wouldn't have passed my time, as this became a practical problem, as well as an exercise of listening to my other than conscious.

So, Did you have any such "ahaa"?