Direct updates on couchbase db goes away

I have a document in couchbase db. Let say
{
“fname”:“abc”,
“lname”:“xyz”
}

Now when i update “fname” to “pqr” from cocuhbase console UI.
it updates it but if i check this after 5 mintues it again reverted to original value.

my questions are:

1: Is this expected behaviour ?
2: If yes, can we override this to retain updated value for forever.