XL 2016 Liste de choix à sélection multiple

Sub ListBox1_Change()
    Dim myListBox As ListBox
    Dim myText As String
    Dim i As Long
    Set myListBox = Feuil1.ListBoxes("List Box 1") 'Pourquoi Feuil1.ListBoxes ?
    With myListBox
        For i = 1 To .ListCount
            If .Selected(i) Then
                myText = myText & ", " & .List(i) 'Tous les champs sélectionnés sont stockés dans myText (ex : P12, P16, P999) ?
            End If
        Next i
        Feuil1.Range(.LinkedCell).Value = Trim(Mid(myText, 2)) 'Pourquoi Feuil1 ? et je n'ai pas compris Trim(Mid(myText, 2).
    End With
End Sub

Sub ListBox1_Change()
    Dim myListBox As ListBox
    Dim myText As String
    Dim i As Long
    Set myListBox = Feuil1.ListBoxes("List Box 1")
    With myListBox
        For i = 1 To .ListCount
            If .Selected(i) Then
                myText = .List(i)
                Sheets("GR1").Cells(2, i + 39) = myText
            End If
            
        Next i
        
    End With
End Sub