The fact is if you practice smart fingering from the start you will save a lot of hassle in the long run, and be a better piano player because of it.
It is only natural to become stressed under the load of everything you are trying to learn, the rhythm and basic notes are tough enough at the start, then when you throw fingering suggestions into the mix it may feel as if the whole thing becomes even tougher.
It can be easy to think that the fingering suggestions make little difference and are just another useless thing you have to learn. This of course isn't the truth, fingering in the score does exist for a reason, although I can see quite clearly why many people will just try to do what comes easier to them. The real question here is are you in the wrong for using a finger other than that recommended, if it sounds the same either way?
The fact is, you are well within your right to do this, you don't have to follow the printed fingerings if you find a way to play the score as it should sound but in a way that is easier for you.
When I was learning the piano myself, I asked the same question of my teacher, who replied by saying it was fine to change fingerings but I should first discuss any changes with her so she could ensure they didn't have negative technical connotations to the way I played the piano.
The fingering directions themselves are almost certainly written by somebody who is far better at the piano than you currently are, they were designed to ensure your hands are in the best position to play the piece as it should be, however this is from the point of view of the person who wrote them, there is nothing wrong with realizing that they are not perfect for your own skill or technique. The best thing to do is ask your teacher about any changes you wish to make and see if you are doing anything wrong from a technical aspect.
To make changes to printed fingering directions without doing anything 'wrong', or to just understand why individual directions are in any given piece in the first place, you need to know a few things about piano fingering:
- When first learning the piano you will almost certainly play pieces that consist of 5 notes for each hand. When doing this you should have each hand in a position where each finger can hit each note that will be needed. An example: for a five note scale in the right hand moving upwards, play the first note with your thumb. As you progress with your level of play you will have to move your hands around more and more as you play more than 5 notes for each hand, however it is always good to try and implement one note for each finger when you can.
- Use your thumb and little finger to play white keys while letting your longer fingers hit the black keys when playing scales or broken chords that require both sets of keys. As you play the piano more you will start to realize the thumb is a good finger to use as a pivot and help you alter hand positions as you play. Each finger is a different shape so remember this and use them accordingly.
- To play the piano well you need to use all 10 of your fingers. There are many pianists out there that overlook their fourth fingers particularly. This is a bad habit to get into so when learning the piano make a conscious effort to use all of your fingers to their full potential, it is hard enough to play with 10 let alone 8! When you first start learning you will quickly see why many overlook these fingers, they are often described as the weakest fingers when playing but this is just even more of a reason to practice with them.
The main thing you need to remember is that finger directions are there to help you, but just blindly following them without knowing the fundamentals behind finger placement is not enough. When you understand the basics you will see why certain directions have been given, and be in a better position to alter them where you wish in a technically sound way.