But if an investor invests regularly in Bitcoin no matter what he does, he will definitely get success
That an investor invested in bitcoin regularly does not give him the passage to do anything with the investment and still have hope of achieving success in it. For an investor to see the success he hoped for in bitcoin, he must observe certain rules, and the most important is for him not to tamper with the investment before the maturity date. If he tampers with the investment before the maturity date, he likely not achieve success with the investment. The ability of an investor to successfully hold his his or her investment to the maturity date, is what will determine if he or she will have success with the investment. I'm referring to long term investors in this case, people who invest and Hodl for a period of at least 5 to 10 years minimum.
You are right and thay is why for an investor not to tamper with his bitcoin investment and be able to hodli for long based on his own time frame, that investor will use part of his discretionary income to invest in bitcoin and also he must have his emergency funds for back up to his bitcoin investment so that when a real emergency arises like a heavy wind pulling of his roof, he will use his emergency funds and not his bitcoin. The investor can still also have a reserve funds to be a back up of his emergency funds.
The investor must also have patience with his bitcoin investment and be consistent with building and growing it regularly without thinking of selling when he sees little profit. Sacrifice and self determination is also need to buy and hodli overtime in order for you to reach your bitcoin target.