My credit score is lower than I expected. Why is this?

My credit score is lower than I expected. Why is this?
Here are some reasons:
– A credit history of fewer than six years, which is the time frame used to calculate your total credit score.
– Missed or late payments over the last six years.
– Holding very few credit accounts means there will be less credit history available on your profile.
– Court judgments or record of insolvency.
– Having a lot of unused credit available could lead to a large balance of debt if you decided to use it all at once.
– Balances on your accounts that are very close to the credit limit indicate that you rely on credit to get through each month.