In this comment I'll use the words useless and "useless". The former's definition is the one we are most familiar with, while the latter, in quotation marks, is the literal definition if you break the word useless into its two components: use + less. So we have of no use whatsoever and of less use. Reminder: I am not using these words as insults, but rather neutrally. Also, I am using the general "you" here, similar to using "one", rather than referring to the reader or the author of the article in specific.
The problem with this article is that you're telling yourself you're not afraid of stupidity, which in this case is synonymous to incompetence or uselessness, yet your endgoal betrays otherwise. You're presenting a bunch of ideas that are 'useless' hoping amongst them is one of more use, hoping it all ties together and produces a wonderful result, as you get to yell "eureka". You do not want to accept uselessness, but to set your expectations of yourself, that either you or another person or persons have imposed, lower, back to where they once were. Or even lower. The reason your or another's expectations of you have risen after becoming older, as many comments have also wrote, is because your effort is being externally recognized by others, either by a Nobel price or a promotion. Regardless, your issue is self-esteem related. To combat lower(ing) self-esteem or insecurity, (and even accept uselessness!), you must love yourself.
Now a question: have you ever loved someone you didn't know at all? I don't mean in the physical sort of attraction, I mean someone that you knew nothing about whatsoever, not even how they look or act. It's impossible, isn't it? It is those we know the best that we feel love for, is it not? Now consider what the opposite of insecurity is. Security in one’s abilities and self, knowledge of one's limits as well as one's capabilities, and an acceptance of who one is. The more one grows, the more they change, so it is possible to know oneself and then not, as it is also possible the view others have make one to muddle their own perception. You won't find confident people who aren't aware of their own abilities or cannot accurately access what tools they have at their disposal. Confidence in abilities one doesn't have is not confidence, but overconfidence, and overconfidence is false confidence, which is as maladaptive as insecurity. I'll focus on those with low self esteem, because you fall into that category; these people are aware of their shortcomings or their potential shortcomings, their 'uselessness', because the higher you are the easier it is to fall, perhaps even inflate how many shortcomings they have. When you accept your "uselessness" you may produce some bad ideas, a few good ones, but in the end the fact that you're ok with it it makes you feel less distress about yourself, does it not?
Tie these together; you cannot love someone you do not know, and people who love themselves know their limits and what they can achieve, to be insecure is to misjudge your achievements, so because of this I assume, could be wrong, you do not love yourself enough. And watch, I said "enough", because knowing oneself completely is impossible. Similar to how reaching the truth is impossible, but becoming less wrong isn't.
Now uselessness. No one likes being bad at something; even babies are afraid of failure. I do not remember my time as a baby, but I remember being frustrated when I couldn't do certain things, like reaching a high place, as a toddler. Perhaps one of the reasons babies cry is because they cannot move their legs by their will. "Uselessness" can be overcome, but sometimes one may be actually useless and never learn how to walk. Does it sting, being called useless? I don't mean it as an insult here. I am using the literal definition of the word; complete inability to do something, rather than partial/subpar. It stings because it has been instilled on one that incompetence is negative, and thus something that should not be a part of you, a flaw needing purification. But if incompetence didn't exist, neither would competence, similarly to how life wouldn't be valuable without death or happiness without sadness.
However I like the gist and the thought behind this article.
Overall, I think acceptance that one might be unable to do certain things, can make one's life easier. The bad ideas you produce are as much of a part of you as your good ones. And accepting both is crucial.