what “ becomes a snap” mean？
If you keep these terms in mind (encoding, storage and retrieval) the concept of memory becomes a snap.

Question

what  “ becomes a snap” mean？
If you keep these terms in mind (encoding, storage and retrieval) the concept of memory becomes a snap.

Answer

"becomes a snap" means that something becomes easy to do. You can also say "is a snap".

... the concept of memory becomes a snap.
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... the concept of memory becomes easy to understand.

Once you get the motion down, juggling is a snap.
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Once you get the motion down, juggling is easy to do.