Hello! This is the topic I have been obsessing with for a long time. I read, experimented, and as of now even taught it for quite a while. Prepare for the long answer:
It is necessary to understand that your mind can and will concentrate in just the manner you described (laser focus and mental clarity). But it needs a good reason to do so.
Yes, you have to trick your brain into concentration mode.
This is why there is no such thing as just pure concentration, because you want it. It needs to be something relating directly to your goals, including life goals in general.
You need to be really curious or perplexed, or accept your ignorance about something. You need to switch off the “I know it all” regime, so that your mind will have to start working.
Concentration is by design goal-directed. It will not work unless it has to do so in order to achieve something. And simply telling yourself “okay, I need to do this” is not gonna work well, you will have to force yourself too much and probably give up.
What works though is if you are working on a project that is important and meaningful for you, your mind will come to your rescue.
And how do you convince your mind that something is important? Not by talking to it. You are talking to yourself. It needs action, it needs to understand that you are the real deal and that you are serious about your intention.
This is why these first 23 minutes of concentration are so important. It takes about 23 minutes for your mind to focus, and any distraction will steer it off and it will take another 20 minutes. Sit down, breather, write down what you need to do and how you are planning to do that. But do not do anything else! You will experience a great pull of forces of distraction, because your mind still thinks that what you are doing is irrelevant to pressing things - food, sex, social needs, chewing on unfinished arguments and worrying. But this wave passes if you do not give in.
And then you get into the mode and can last for hours on end. Better yet, once you are drained of mental energy and go about other things, your mind will unconsciously keep working on a problem you just spent hours on. It is now convinced it is important and will take it seriously, even working on solutions in your sleep, or if it is something rather experiential, it will complexify your mental maps of this experience, without you even knowing before you go back to the task the next time, or do related things.
I write about this extensively elsewhere, including specific regiments, but cannot post or link it it here.