Sure if you have long term investment ideas, then you would likely not be selling any of your bitcoin now, but I doubt that the reason would merely be because you expect profits to be guaranteed in the future, but instead that you had made your investment into bitcoin based on a long term investment thesis and you are not merely thinking about short term profits.
That's a decent thesis to follow, a lot of people have regretted not getting into bitcoin and they're not really that into missing out again if they can help it, plus it's the easiest thesis to follow when it comes to bitcoin investing, all you need is patience to wait for your bitcoin price to come and then buy again when the price starts going down and setting another goal.
On the other hand, if you come into bitcoin and you do not have solid ideas for what might be your investment thesis, and you might not even know why you like bitcoin except for thinking that it could make you some money, then you likely would be more inclined to sell at various points along the way, and you might not really realize that you could sell in increments, but instead you think about either being in or out, and so it could look very attractive to get 40% to 60% profits in less than a couple of months.
Totally agree, not knowing where you stand in something will ultimately be your downfall and in the case of bitcoin investment, neutral or indecisive stance will lead to losses and discouragement from investing in something ever again. If you don't like complications, just follow the first investing thesis since you don't have to work too much in terms of analysis there but do what works best for you.