Welcome aboard for our journey with Go's maps. Maps, a built-in data type, make it easy to organize and find data within collections — a crucial feature for effective programming.

In Go, maps link one value (the key) to another value. Just imagine having a roster of students alongside their grades. With maps, you can quickly associate each student (the key) with their corresponding grade (the value).

Our quest today involves the following:

• Understanding how to craft and initiate Go's maps.
• Learning to interact with map elements.
• Fathoming the external behavior of maps as reference types in Go.

Let's dive in!

Declaring a map in Go is as easy as pie. For this purpose, you can utilize either the make function or a composite literal. Let's sketch an illustration:

Go
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1// Using the make function
2var grades1 = make(map[string]int)
3
4// Using composite literal syntax
5var grades2 = map[string]int{}
6
7// Pre-populated map using composite literal syntax
8var grades3 = map[string]int{"John": 85, "Jane": 90}

As displayed above, we create maps that accommodate strings as keys and integers as their associated values.

Go's maps enable swift and effortless handling of map elements. Adding, changing, accessing values, or handling absent keys in a map is a cinch:

Go
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1var grades = make(map[string]int)
2grades["John"] = 85   // Store John's grade in the map
3grades["Jane"] = 90   // Store Jane's grade
4
5johnGrade := grades["John"]     // Retrieve John's grade
6grades["John"] = 95             // Update John's grade
7
8delete(grades, "John")            // Delete John's entry
9johnGrade, johnExists := grades["John"]   // Check if John's grade exists
10if (johnExists) {
11    fmt.Println(johnGrade)  // won't execute, as John was deleted
12}

Notice how we use the key to access, update or delete an element. It is much more handy then indicies in the array. We can access "John"'s grade using his own name as an identifier!

Since maps are reference types in Go, assigning a map to a new map variable creates a reference, not a replica:

Go
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1var originalData = map[string]int{"apple": 1, "banana": 2}
2var copiedData = originalData
3copiedData["apple"] = 100
4
5fmt.Println(originalData)
6fmt.Println(copiedData)

The output of both maps reflects the value 100 related to "apple". Here, copiedData is simply a reference to originalData, hence modifications enacted on copiedData affect originalData.

Well done! Today, you've unlocked a potent element of Go's treasury — maps! By navigating through map declaration and initialization, manipulating elements, and gaining insight into map behavior, you've garnered a rich facet of Go.

What's next in line are exercises for you to practice, reiterate, and reinforce what you've learned today. Get ready to dive in and soak up the allure of Go! Be sure to tackle the upcoming exercises — they're designed to help you solidify these new skills. Happy coding!