Fantastic Vent!
And now for some of that advice you asked for.
First off I'd like to congratulate you on finally getting to meet Mr. Know-It-All the other day. Actually, his family is all that way, and there's 100's of them. There isn't much you'll ever be able to do better than them, so just bow to the greatest and ignore them. A great lesson for a happy life is that "actions speak louder than words".
Having said that brings me to the next subject of SECRET SPOTS!!!!
If you decide that you are going to enter the world of tournament fishing, you are going to face an issue that every other tournament fisherman does. And right off the bat, I'm going to tell you that there is no such thing as a secret spot on any public body of water. But there is an easy and fair way to approach this issue, and it deals with respect. Respect is not just a word, but to me it is lifestyle choice. If you decide that you will treat everyone you meet in life with it, you'll earn a lot of it back.
Anyhow, the subject of spots is an ongoing frustration to a lot of tournament anglers. In some ways it is understandable, but in many others it approaches the ridiculous. So I suggest that you adopt the two basic rules that I've always lived by. It may not make others happy, but then again, you can't please everyone.
Rule #1 - Don't Act Like A Seagull:
Quite simply, if you see someone sitting on a spot that is just hammering the fish, resist the urge to sneak right into that area to join in on the fun. If someone is working a shoreline, or a line of docks, don't jump in front of them. If you really want to fish that same area, you really need to start way behind them, or start behind them and work the other way. This is a really simple rule to follow because all you have to do is to think about how you would feel if someone was doing it to you.
Rule #2 - Respect Your Teacher!
If you go fishing with someone else and they take you to an area that they tell you something like "This is one of my favorite spots!", then you need to show them a little respect when the day comes that the two of you are competing against each other. Before the tournament, go up and ask the guy about it. If they say that they plan on starting somewhere they showed you, or if they say they plan on going to a spot at such and such a time when they expect the fish to turn on there..... LEAVE THE SPOT ALONE! And that includes any prefishing time before the tournament. Resist the urge to go back to these places the day before the tournament just to find out "How's my buddy going to do?". This is another easy rule to follow. Imagine that you introduce your girlfriend to your buddy, and when you get home from the lake he's at her house sparking with your gal. Does that sound outrageous? Of course it does, but with a lot of guys (regardless of age) think their spots rank one or two spots above the woman in their lives.
Rule #3 - There Isn't One!
Aside from either of the above, anyplace you fish, is going to be something that your knowledge, your time spent in map study, or your time spent on the water searching, is going to be the result of your efforts. It doesn't matter where you find to spend your tournament day, someone has been there before you. If you get to that spot first, then fish it.
You may have someone tell you that this is their spot, but you have the simple reply: "How would I have known that?" On a public body of water, no one "owns" their spot. And you can trust me that you WILL get to the point where the tables are turned. You'll pre-fish for a tournament someday where you find the "perfect spot". And the morning of the tournament you'll draw the dead last blast off number. That's the way the cookie crumbles, and unless it is a friend of yours sitting there, you will just need to move on.
My final piece of advice deals with your buddy's Dad, and maybe with everyone else as well. In a very respectful way, you tell them that some wise Ol' Yankee Know-It-All took the time to read my really long vent, and then took the time to write an even longer reply. Explain to him the rules (and these don't have to be it) that you plan to live by when you become a tournament fisherman.
And now go out and make your own magic..... Good Luck!