How memories relate to tombs

The verb μναομαι (mnaomai) means to remember, to recollect or to be mindful (hence our English adjective "mnemonic"). It's used in the New Testament with pretty much the same nuances and applications as our English verb, from abruptly recalling something out of one's own memory (Matthew 5:23, 26:75, John 2:22), to reviewing one's memory in a controlled way (Acts 11:16, 2 Timothy 1:4, 2 Peter 3:2), to keeping continuously in one's conscious mind (1 Corinthians 11:2, Luke 24:6).

A first century tomb: not exactly a memorial but still known as one -- why?

The derived noun μνημα (mnema) denotes a memorial or monument. In the New Testament this word is used 8 times, see full concordance, and solely to describe a tomb. Since Jewish tradition didn't really sport tomb stones, this word seems to demonstrate that a slowly decaying body in a tomb was seen as something closely similar to a fixed memory in one's mind (how the English language acquired its phrase "skeleton in the closet" is not clear but it's doubtlessly a Jewish contribution; also see Ezekiel 37:1-14).

Note that the demoniac called Legion lived among these "items of remembrance" according to the Lucan evangelist (Luke 8:27), and this may indicate that this man was not only suffering from a demonic infestation, he was also living among the memories of a painful past and doubtlessly burdened by severe psychological trauma. Also note that a similar double meaning exists in the verb κατατιθημι (katatithemi), which means both to inter and to be remembered (favorably).

Keep reading:

http://www.abarim-publications.com/DictionaryG/m/m-n-a-o-m-a-i.html