Sometimes some people tell to not "reinvent the wheel" by creating things that already exists. It's been time to clarify why we should reinvent the wheel and why they are wrong!
The best argument you can say in this situation is that you want to learn. Revolutionary ideas don't come that easy, if you want to learn just do something you would like to do, don't focus on creating new things especially.
You need skills to create your ideas. Get those skills by doing anything that comes in your mind!
Doing something that already exists can make yourself understand how it works and how can it be improved. Things are not perfects but are perfectibles, let's see the smartphone industry for instance.
You reinvent the wheel? So what? Peoples should not lead you in unwanted situations. Just have fun making things. Doesn't matter if those already exists, at least you'll be happy and that's what matters the most.
The metaphor "don't reinvent the wheel" is so wrong! The wheel, strictly speaking, has been reinvented tons of times. We didn't come with a full rubber wheel in high technology cars in the first try. Things evolves because peoples "reinvent the wheel", and it should continue like that.
In conclusion, just improve yourself without thinking about making a brand new idea. It's ain't easy to find something that haven't been created yet so don't think too much about it if your only goal is to discover and explore new things.
Ideas comes with discovery.
Discoveries comes with time.