How a good user experience should make you feel!
Great user experience is a very bold goal but it can be achieved!
First, let’s analyze what makes a UI “good”
Learnability
In an ideal user interface users remember and can replicate every function after a single action. As designers, we should always strive to make things easy for users to learn!

Affordance
Affordance means the interaction must speak for itself, by suggesting its own use. Affordance is one of the most important things in order to have an easy user interface; it saves the users’ time from wandering around in an application, trying to figure what each and every button does. Users need to have a clear understanding of what a button does even before they think of tapping it.

Consistency
Another very important part of what makes a user interface great is consistency. A successful interaction is one that boils down complexity and helps users to predict what’s coming next.

Discoverability
This one is pretty self-explanatory; all applications, no matter if they are web-based or mobile, include some complex parts at some point, which many designers commonly try to hide inside their designs. This will only frustrate users and not help them. Put yourself in their shoes for a second: if you want to achieve something that you know an application can do, but can’t find out how to do it, how do you feel at this exact moment?
Not the best feeling right? You don’t want your users to feel like this! The solution is simple…

“Stop trying to hide complex parts of an application and just make them simpler!”
These are 4 key points that can be found in a “good UI”.
I don’t know if you have noticed but each and every one of the above elements derives from each other.
To make it simpler:
“For a user interface to be Learnable, it needs to have high Affordance levels; in order to have high Affordance levels, a user interface needs to be Consistent. Finally, a user interface that is Consistent, it’s easy for a user to explore and thus it is Discoverable.”
The conclusion?
A good user experience should feel familiar, something like
when you get up at night to go to the bathroom and all the lights are turned off and somehow you managed to navigate through and made it to the bathroom, why? because it is your house and it is familiar to you, you know where each and everything is.
And this is the reason that never happens on another place you may be a guest at, and most likely you will stumble your pinky!Don’t let users stumble their toes, make them feel at home!
~ Test Fail Iterate Repeat ~