Every trader goes on a journey exploring various strategies in trading. You may watch YouTube videos, read books, and do a lot of backtesting. Eventually, the time comes to define your strategy and begin trading. Whether you are systematic, discretionary, or a combination, at this point you need to write down your rules. Your constraints will help determine which strategies and rules are actually possible for you to adhere to.
Are you able to view the market at the end of each day with consistency? If not, perhaps you need to ensure you have stop losses in the market and you can’t only stop on close. Perhaps you need to enter with orders rather than entering at the close. Maybe you need to only execute at the end of the week or the end of the month.
Are you able to watch the market for multiple hours a day? If not, perhaps you shouldn’t focus on day trading.
Are you able to withstand 30-40% drawdowns? If not, perhaps that trend following strategy that did so well in backtests is not for you.
Can you watch a trade go from a big profit back to breakeven or a loss? If not, maybe you need tighter stops.
This is where the hard reality of trading clashes with the fantasy of the returns that you’ve seen in your backtesting or research.