How can we নিশ্চিত that Bambi was actually Walt Disney’s পছন্দ ডিজনি film as ব্যক্ত দ্বারা 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 ব্যক্ত that they 'believe' that it was was his favorite, but that's not knowing for sure. Otherwise, they would've ব্যক্ত that it's his পছন্দ rather than adding "believe" with it.
I do know that Diane(his only biological daughter) is ব্যক্ত that her পছন্দ movie was Fantasia as I heard she even attended a I think it was 70th anniversary of Fantasia.
Any proof আপনি have on her father's পছন্দ film though?