Button Text and Booleans (Simple Android App)

I'm build the Fun Facts app on the Android Development Track. I decided to take a exploratory detour and try to create a very basic introductory message to the user. I changed the factTextView text to "You can click the button below to see a new fact!" and changed the showFactButton text to "Try it out!"

From there, I changed the final line onClick object (is that an object?) to the following:

        public void onClick(View view) {
            String fact = mFactBook.getFact();
            // Update the label with our dynamic fact
            factLabel.setText(fact);
            // Set button text to new fact prompt
            showFactButton.setText("Show another fun fact.");

This seems to work fine. However, I feel like "updating" the button text to the same new string on every press isn't always the best practice, even if it is easy and readable. I tried to add a boolean that will check the text of the button, and update it only if it has not already been updated. This is what I've come up with so far:

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public String launchText = getResources().getString(R.string.start_text);
        public String nextText = getResources().getString(R.string.next_text);
        public String buttonText = (String) showFactButton.getText();
        public boolean updateLaunchText() {
            if (buttonText.equals(launchText)) {
                buttonText.replaceAll(launchText, nextText);
                return true;
            }
            else {
                return true;
            }
        }
        public void onClick(View view) {
            String fact = mFactBook.getFact();
            // Update the label with our dynamic fact
            factLabel.setText(fact);
        }
    };

With the following added to strings.xml:

<string name="start_text">Try it out!</string>
<string name="next_text">Show another Fun Fact!</string>

No errors, but the button text stays on "Try it out!" I'm sure that all the extra objects are totally unnecessary compared to the first, working method for the scope of this app, but I'd still like to figure it out since I don't really have any idea what I'm doing with the boolean.

Questions: 1) What am I missing in the longer boolean approach? 2) What's the actual most efficient approach to accomplish this task?