From Psalm 137, "If I forget thee, O Jerusalem, let my right hand forget her cunning."
Take "Jerusalem" to mean the heavenlies, or the things that are above. Watchfulness (attention or focus) is the key to the spiritual life. Being watchful can be taken to mean not forgetting about something. Another familiar verse to go along with this is from Isaiah 62, "I have set watchmen upon thy walls, O Jerusalem, which shall never hold their peace day nor night: ye that make mention of the Lord, (margin "the Lord's remembrancers"), keep not silence, And give Him no rest, till He establish, and till He make Jerusalem a praise in the earth."
In other words, there are those called to hold the Lord in their memory constantly. Therefore, watching is tied to the memory, and spiritually speaking, I believe you have to make a choice to retain the Lord in your memory or thoughts, and not to be in a state of forgetfulness of Him.
I believe Scripture is admonishing us to not be forgetful of the higher life or our Lord.
Another thing to remember:
Another thing to remember:
I believe "remembrance" of our mortality is one of the key things in the spiritual life. I always go back to the verses, "Lord teach us to number our days, that we might apply our hearts unto wisdom", Psalm 90:12; and also, "Go to now, ye that say, To day or to morrow we will go into such a city, and continue there a year, and buy and sell, and get gain: Whereas ye know not what shall be on the morrow. For what is your life? It is even a vapour, that appeareth for a little time, and then vanisheth away. James 4:13,14.
I believe it is a foundation of wisdom to keep our mortality always before us. It keeps us directly in the present moment, and also saves us from many projections of "big ideas" or visions for the future, that may not be led of the Spirit.
In 1989 I had a suspicious test result, that proved to be benign, but I was unable to find that out for about three weeks. For some reason there were complications with tests results and the doctors were uncertain about it. I really came face to face with my mortality during that time. The Lord really used it to shake me profoundly, and I came out of it in a new place. I count it as a great blessing looking back on it.
On another note, there is another side to this. There can be a really good forgetfulness. From Isaiah 43:18, "Remember ye not the former things, neither consider the things of old, Behold, I will do a new thing, now it shall spring forth..." And where would we be without the divine forgetfulness of our sins? For He has said in His covenant promise, ".... their sins and iniquities will I remember no more." Hebrews 10:17.