A recent commercial reminded me that while simple tasks and such are often easy, sometimes the two qualities do not coexist. Of course, whether you think something is simple can depend on point of view, such as with losing weight.
What can you think of that’s simple, but not easy, and vice versa?
Simple but not easy: Stand on one foot and balance for a long time.
Easy but not simple: My job. Many, many fiddly little tasks that I’ve memorized and streamlined down through the years that I can do it in my sleep, but it’d take me a month to teach you how to do it.
It’s simple, but not easy, to be dumb but not stupid.
It’s easy, but not simple, to be stupid but not dumb.
Threading a needle is pretty simple, but not easy.
Quitting smoking is simple. You just stop getting cigarettes and smoking them.
It is not easy.
Sure: playing a simple musical phrase on an instrument. Many famous leads are simple melodic phrases that beginners can play, but making the notes truly sing…that’s a bit harder.
Miles Davis’ Kind of Blue is held up as the most beloved jazz album of all time. It is known for having long, languid, melodic trumpet playing by Miles. His whole approach to the album - described as “modal playing” - was all about slowing things down and not giving the players the typical chord changes they could blast superfast leads over.
The notes are easy. The music - and the spaces between the notes - are hard.
As I always say about music: Simpler is Better; Less is More
I believe the Haiku poetry form embodies this approach, too.
Doh, didn’t read the OP properly.
Caring for a newborn is simple, but enormously difficult.
Juggling is also simple, but not easy, until you have practiced a lot.
Simple but not easy: writing a well-crafted pop song.
mmm
ETA: Similar to what **WordMan **said
Not simple, but easy: driving a car. Even the first time you’re behind the wheel, most of us do okay. There’s room for improvement, but if you consider the insanely complex task that driving a car actually is - with constantly changing visual and auditory input and motor output coordinating hands and feet and arm movements while following directions and being aware of what everyone around you is also doing to change the environment… there’s nothing simple about the mechanics of driving. Thank goodness most of the math and physics is done unconsciously.
Simple, but not (always) easy: peeling hard boiled eggs. (I really like the threading a needle example, too.)
Some complex tasks can get easy with time due to muscle memory, such as typing. I type 60 WPM and I’m not really sure how.
Filling out a winning lottery .ticket
I can tell you from personal experience: being a store cashier is simple, but it is not easy.
Simple, but not easy! 
Being “yourself” is simple, but not easy.
Most engine repairs are easy, but not simple, provided you have all the correct tools. That is really what you pay a mechanic for-- he has a huge array of specialized tools.
Simple: bring virtually all conflict in the Middle East to an end by having everyone respect and tolerate each others’ religious beliefs.
Easy: uh…:dubious:
Chess is simple to learn (just the moves of 6 pieces), but certainly not easy to play well.
Breaking or developing habits is simple but not easy.
Free verse is simple but not easy.
Language, for most of us, is easy, but not simple. Communication in general is easy but not simple (communicating exactly what you want is not always either!)
Touche! 