Why people quit?

Because once they lose some of investment, their mind change to "I'm gonna get the money back."

This is totally wrong.

Once you think this way, the next step you will have in mind is "I'm going to get even and get out."

Then when you lose more, you will turn into emotional (if you are emotional, you are already a loser in stock investment or speculation) and bet big without precaution, study, and due diligent.

You should always think "I'm here to make money."

Whether you are down from the initial investment. You must think, "I'm here to make money."

Trust yourself.