the word overlap is so confusing.
I know its lexical meaning. One is to cover partly. The other is to partly coincide in time. But I still can't figure out the meaning of this sentence:
"Our music tastes don't overlap at all. "

Does that mean their music tastes are "mostly different" or "mostly the same"?

Question

the word overlap is so confusing.
I know its lexical meaning. One is to cover partly. The other is to partly coincide in time. But I still can't figure out the meaning of this sentence: 
"Our music tastes don't overlap at all. "

Does that mean their music tastes are "mostly different" or "mostly the same"?

Answer

In that sentence, their music tastes are completely different because they don't overlap at all. If there wasn't the at all part, it would be ''mostly different''.

Answer

if you say "don't overlap" in this case, it's like saying that they're not the same or they don't coincide with.

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