"The mind is a chaotic database" Pt. 1

This is my first blog post. I'm starting this mainly for myself, to keep track of my own thoughts. If I happen to get a few subscribers, I will try and keep up with my posts. But at this time, I cannot ensure the fact that I would keep writing on this blog.

Moving on...About a month ago, I had an interview at a consulting company in the GTA. During the interview process, I was asked several technical design questions. The first one was "draw an inverting amplifier [using op-amps]". This was quite easy, I must say. But the question that stumped me, was to connect an LED to the output pin of a micro-controller. And it is known that the output voltage on that pin is 3.3 volts. I had to make the observation that this potential was not enough to power the LED. OK, so I can't just connect the LED straight to the pin and expect it to work. I proposed to add the amplifier drawn in the first question, with a specific gain to be able to power the LED.
At the time I thought my design idea was great, and that I did very well at the interview without giving it a second thought.

I'll tell you now that I did not get the job, for several reasons I'm in no mood to mention.
Three nights ago, just after lying in bed for less than 5 minutes, for no logical reason, I thought of another much better design circuit for that question. I wasn't even thinking about the question, or asking myself if I could find a more efficient solution. NO, the solution was the first thing to pop into my head. Which made me realize how the mind is a chaotic database. I am more stunned by how I had no control on my own train of thoughts. A normal person would ask himself if there's a better way to implement this LED circuit, then put his/her thoughts to use. I seem to have skipped this normal pattern of behavior and went straight to a solution. Now this may not seem like a bad thing, "I found the solution to a problem even without thinking about it".
I'll get to this point in a bit, but here is the alternative solution which is better than the one I had provided during my interview. Simply use an NPN BJT, where the output of the micro-processor is at the base, and the LED at the emitter. The collect is driven by a source enough to power the LED (ie: 5 volts). A BJT is much cheaper and smaller then an Op-amp which comes usually in an IC and usually includes 2 op-amps. Why didn't I think of that at the interview? Could be just the pressure to perform on such short notice, but I don't blame myself for that. Any smarter person would have probably given a million better designs than my op-amp configuration.

It is on this note that I shall retire. I will come come back and dwell on this later.

Cheers,
Mystro