I agree. If you want to stay a small retail trader forever and are happy there then your strategy works. Very very high risk. Essentially, you are risking your money in full 'riding your jetski at full tilt'. Any shift in the wind direction, change in the slalom, change in rules of the slalom,mechanical issues or even driver error...using your analogy.... can set you back a lot and hurt you personally.
The risk/reward is different, of course, if you manage OPM (other people's money) on a success- fee basis (heads we win, tails you lose).
People forget that the hedge fund titans are really very risk averse with their own net-worths in general. Once they scale up, the absolute worst thing that can happen is that they blow up, they return the money and apologize. They get to keep the house in the Hamptons, the trophy wife, mistress and a good lifestyle. In fact, many go on to set up funds again. The reason why is that they transfer risk onto their clients (heads we win, tails we lose) just like I did on a smaller scale as a broker/portfolio manager. All the 'market wizards' worked that way (something nobody tells you).
Here is an example money manager apology...he is crying at the end. If you lose your money expect such an apology. However, he will never take out money from his personal account or sell his expensive watch to pay you the money back you lost. This case study is not a true hedge fund manager but a commodity options trading firm which went bust but illustrates a point.
This is what Zeno alluded to in previous posts, they can run a game called 'survivorship bias'. This is where you set up...say....5 funds. Four fail and you quickly roll them into the fifth. Now you market yourself as a genius because one of the funds had stellar returns and attract more money.
A retail day trader, riding his jetski can in fact lose his house, car, wife and yes...even his non-metaphorical jetski or mistress if he has worked hard enough to afford one. A different risk.reward equation.
Here is another example, on the retail level. A very crude and simple example....you set up 10 online investor accounts on a social investing site. You use a martingale strategy. 9 blow up (but nobody knows it was you who set them up). The 10th has a 300% return over 1 month and you loudly proclaim to the world that you are a genius/brilliant. You are a guru now and can attract dumb money, sell courses etc.