How can we xác nhận that Bambi was actually Walt Disney’s yêu thích Disney film as đã đưa ý kiến bởi some people?(read description)

Well that's what I hear, but where exactly is the proof though? I haven't found any biography based stuff like if Walt ever personally mentioned it was his 'favorite'. The only thing I've found is in a Making of Bambi video where two of creators đã đưa ý kiến that they 'believe' that it was was his favorite, but that's not knowing for sure. Otherwise, they would've đã đưa ý kiến that it's his yêu thích rather than adding "believe" with it.
I do know that Diane(his only biological daughter) is đã đưa ý kiến that her yêu thích movie was Fantasia as I heard she even attended a I think it was 70th anniversary of Fantasia.
Any proof bạn have on her father's yêu thích film though?