The Lord knows all things and, for him, it is as if all things in time are happening all at once:
The same which knoweth all things, for all things are present before mine eyes; (D&C 38:2)
...all things are present with me, for I know them all. (Moses 1:6)
13 The Lord looketh from heaven; he beholdeth all the sons of men.
14 From the place of his habitation he looketh upon all the inhabitants of the earth.
15 He fashioneth their hearts alike; he considereth all their works. (Psalm 33)
2 Thou knowest my downsitting and mine uprising, thou understandest my thought afar off.
3 Thou compassest my path and my lying down, and art acquainted with all my ways. (Psalm 139)
Can any hide himself in secret places that I shall not see him? saith the Lord. Do not I fill heaven and earth? saith the Lord. (Jeremiah 23:24)
Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him. (Matthew 6:8)
12 For the word of God is quick, and powerful, and sharper than any two-edged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.
13 Neither is there any creature that is not manifest in his sight: but all things are naked and opened unto the eyes of him with whom we have to do. (Hebrews 4)
For mine eyes are upon all their ways: they are not hid from my face, neither is their iniquity hid from mine eyes. (Jeremiah 16:17)
Declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure: (Isaiah 46:10)
And who, as I, shall call, and shall declare it, and set it in order for me, since I appointed the ancient people? and the things that are coming, and shall come, let them shew unto them. (Isaiah 44:7)
Because God knows all things and all things are present before him continually, he is constantly aware of all joy, all sorrow, all pleasure, and all pain. This tells us a lot about God and about positive and negative things. It tells us that God has a way to feel complete joy even when exposed to complete sorrow, to feel complete pleasure in spite of also feeling complete pain. It tells us that God possesses the tools to interpret these experiences in a way that does not prevent him from having not only a net positive experience, but greater joy and happiness than any of us have ever experienced. While other chapters discuss some of these ideas, here we will focus on the idea of having all things before you continually.