Cannot resolve Symbol variables - Tearing my hair out - variables

Question

I am trying to follow a tutorial and have got stuck with what I figure to be the last error before completion.
Can someone tell me what I am doing wrong with these variables?
Including both activities below, if any other code is applicable, I am happy to provide it.
Error codes read:
Error:(21, 56) error: cannot find symbol variable pickupLine
Error:(24, 9) error: cannot find symbol variable retryButton
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
Compilation failed; see the compiler error output for details.
MainActivity.java:
package io.wavey.pickuplesson1;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Grab clean button so we can do stuff with it!
Button cleanButton = (Button) findViewById(R.id.cleanButton);
final Button dirtyButton = (Button) findViewById(R.id.dirtyButton);
final String pickupLine = "You had me at hello world";
//This is a Callback.
cleanButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sendLine(pickupLine);
}
});
}
//Send to activity
private void sendLine(String pickupLine) {
Intent intent = new Intent(this, LineActivity.class);
intent.putExtra("Pickup Line", pickupLine);
startActivity(intent);
}
}
LineActivity.java:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_line);
Bundle pickupData = getIntent().getExtras();
if (pickupData == null) {
return;
}
String receivedPickupLine = pickupData.getString("Pickup Line");
TextView newLine = (TextView) findViewById(R.id.pickupLine);
newLine.setText(receivedPickupLine);
retryButton.setOnClicklistener (new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
}
}
LineActivity.java: