Scripture says both, REMEMBER and DO NOT REMEMBER THE PAST. There is a kind of selective memory that is good. REMEMBER the things that draw us CLOSER TO GOD.
FORGET the things that move us away from God.
God has selective memory. He remembers the sins of the unsaved, but not the sins of the saved. Selective memory is not a cognitive failure, it is a choice of the will.
Not Contradictory, But Complimentary
There is both a negative and a positive side to reflecting on the past.
The Negative Side...
Do not live in the past,
Do not long for the past,
Do not loath the past.
Verses...
Ecclesiastes 7:10
10 Say not thou, What is the cause that the former days were better than these? for thou dost not inquire wisely concerning this.
Isiah 43:18-19
18 Remember ye not the former things, neither consider the things of old.
19 Behold, I will do a new thing; now it shall spring forth; shall ye not know it? I will even make a way in the wilderness, and rivers in the desert.
Philippians 3:13-14
13 Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before,
14 I press toward the mark for the prize of the high calling of God in Christ Jesus.
Instead,
The Positive Side...
Learn from the Past,
Verses...
2 Peter 1:12-13
12 Wherefore I will not be negligent to put you always in remembrance of these things, though ye know them, and be established in the present truth.
13 Yea, I think it meet, as long as I am in this tabernacle, to stir you up by putting you in remembrance;
Psalm 77:11
11 I will remember the works of the LORD: surely I will remember thy wonders of old.
Psalm 103:2
2 Bless the LORD, O my soul, and forget not all his benefits:
Psalm 105:4-5
4 Seek the LORD, and his strength: seek his face evermore.
5 Remember his marvelous works that he hath done; his wonders, and the judgments of his mouth;
Psalm 143:5-6
5 I remember the days of old; I meditate on all thy works; I muse on the work of thy hands.
6 I stretch forth my hands unto thee: my soul thirsts after thee, as a thirsty land. Selah.
Ecclesiastes 12:1
1 Remember now thy Creator in the days of thy youth, while the evil days come not, nor the years draw nigh, when thou shalt say, I have no pleasure in them;
Isaiah 46:9-10
9 Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me,
10 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:
Ephesians 2:11-13
11 Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
