This how I started (35 years ago):
(1) I had a request (from a buyer, the first one) to build a simple on/off light controller for 220Vac 1000W bulbs (though now most people uses LEDs). It was one of the most important exams I had to pass. There was no question to fail for two reasons; I had to prove to myself that I can build something (simple or not) to be useful for others the way they like, and I had the impression that it may be the first circuit of the private business I was looking to start (and it was!)
(2) I had, at that time, a multi-meter only. So there was no way to see the shape of any signal other than measuring the DC value and in a way the AC strength. It took me about 2 months to find out that I was connecting the electrolytic capacitor at the supply output with the wrong polarity. So no matter how I redesigned the circuit, the unseen high ripple voltage prevented it to work properly. But I was ready to keep trying forever to find out the reason of the circuit failure! In other words, for me, withdrawing or shifting to another project was absolutely out of question too.
(3) My first goal was to make products that run properly (exactly as I like them to do, actually as requested by the customer). It didn’t (even till now) matter for me if my work or solution is the best or not in the world as long it is the best in my surroundings and in some respects in the least. I don’t try to imitate in my designs any other’s work while I also don’t try to re-invent the wheel if I can buy it and added to my project.
What I have just written may apply to those who may be able to start their own private business/company. But to those who look to work in a company, things are likely very different, I guess.
Kerim