Is psionics a simple side effect that comes with knowledge of "reality"??
I recall stolide once responding to a question about fireballs: "
Seriously though, by the time one would be good enough to do so, you would not care about such things."
Sorry to put you on the spot, Stolide 
So by the time we are able to do such things, we wouldn't worry about fireballs etc. and I completely agree.
So does that mean that it is not possible to be good at psionics without basically realizing "reality"? So would it help to try and work on that aspect rather than begin with psiwheels etc?
You seem to be asking if ability is a side effect of knowledge, but does knowing how a bike is put together or its purpose mean that one can ride it? The answer is no. On the other hand, does one need to know how to put together a bike to ride it? The answer is no. Stolide's answer is also unreasonable. If the purpose of x is to do y, and one does not need to do y, then there is no reason why a person should pursue x since y, which x leads to, is ultimately meaningless. Putting in the context, if how to do something is done with the purpose of making fireballs, and a person realizes that making fireballs is not important, then there is no reason to continue learning to make fireballs. Worst yet, a person can spend 10 years learning how to make a fireball only to realize that making one is pointless so they have wasted 10 years they could have been using for something else. Statements like the fireball one are made to save face due to the fact that the person doesn't know how to do the thing in question. Run away from people who give such responses.
Psychic abilities are rooted in tacit and not semantic nor explicit knowledge. This means that knowledge that or of something doesn't mean knowledge how, so, no, knowledge about the dynamics of something does not lead to the ability to do it anymore than knowledge of the mechanics of a car leads to the ability to drive one. Furthermore, psychic abilities are teleological in nature. They are goal or purpose oriented, so if something is meaningless, then there is nothing for it to be aimed at thus no effect happens.
The underlying idea of psionics is flawed due to the very mechanics of it. Psionics is a combination of the word psi and electronics in which the idea is that psi can be used as consistently as machine thereby creating an implicit idea of mechanism or determinism. An example of this thinking is the idea that psi is the result of complex factors in which if we learn it we can produce an effect every time. This is totally and utterly incorrect due to the fact that organic systems are stochastic and non deterministic systems, thus, there is no mechanical nature to usage psi where you will always have indeterminate and truly random fluctuations. Enzymatic reactions, hormonal oscillations, protein folding and expression, and neural activity are all stochastic, not mechanical or non deterministic; therefore, there can be no underlying mechanical nature to it. This also gives the illusions that it is a byproduct, derived, or reducible which is also incorrect. In short, no, psychic ability is not a derived or reduced property of something; it is fundamental. Knowledge of what or of or that is not knowledge of how, so, no, knowledge of the theory won't give psychic abilities.
