If you have a trading plan, you will always know when and how to trade the market.
You will know with confidence where to place your trades, take your profits, and cut your losses.
Your trading plan primarily consists of one or more trading strategies and trading rules.
Why is this important?
Having a trading plan makes trading easy, and it takes out the thrill, anxiety, and complexity of trading.
When you don't have a trading plan and trade on hunches, you'll more likely want to try a new strategy as soon as the one you're currently trading "stops" working.
Most beginner traders will usually jump from one strategy to another every other week.
You'll be a jack of all trades but master of none.
Suppose you continuously jump from one strategy to another in the hope of finding the Holy Grail.
In that case, you are running on false hopes.
As a result of this endless jumping around, you'll continue to lose money and then give up.