The 3 fundmental details of psionics is what will help people to learn their abilities without having to worry about how long in years it will take them. It will also give them a chance to let them take a break, since advancing in any ability is not a race, but it is something that each individual would want to see within themselves.
For those starting out psionics as beginners, an open mind to any ability is extremely important, as it will unlock the deeper parts in your inner self to set your path of becoming a energy user. Keep this in mind when practicing, or even when people knock you down with discouragements and belief. Keep a 'can do attitude' for the hard work you are doing.
For this area, the user is thinking about in terms of weeks, months, or years of how better they will become. This is my way: Do not think about the time, otherwise you'll end up quitting, and achieving nothing. Think of it like a natural talent. Take time off from training to recover your strength, and realize that it is not a game or a race, but more of like going under development of your true self. Again: don't think about how long something will take you. Your concentration should be around sharp and intense. The more it is, the better the chance you will get a result on, but stay patient when doing so because concentration is something that is hard at first, but becomes easier the more you do it. Just never let go.
Determination is the act of keep on going on the goal you set yourself up with and becoming a successful person in any goal you have thought of. That would mean if your goal is to levitate objects with Telekinesis, then keep pressing forward till you meet that goal. If you wanted to move cars, teleport, or even walking through material, then determination is the 3rd key of this fundmental of psionics. It's about not giving up, or stopping, but to see and be proud of that goal which you have kept on battling to get to. Like said above, don't think about how long it will take, just enjoy the process.