Anything New Takes Practice
Learning to do a so-called simple thing can be experienced as difficult as learning a so-called complex thing (such as solving a differential equation or cooking a new recipe) because in both cases, they are NEW. And it's the newness, the "not having tried before" that can make something feel hard. The difficulty is not always a function of how seemingly complex something is and/or the number of steps to finish it.
Being in the Flow is Where Easiness Resides
And once in the flow!! Well, life will indeed feel easier simply because an intrinsic part of "being in the flow" is the lack of resistance. Resistance is a big contributor to why simple things can feel hard (related to the new-ness factor). Resistance is a signal of fear. And it's very natural to feel some fear when trying something new, when you are not sure of whether you can do it. The good news is that with practice, you WILL get better at anything you set your mind to - and getting better IS success!
You Can Learn to Find Ease More Quickly
So, YES things that are hard now get easier. And since we are always growing there will be new challenges that seem just as hard at first. But remember you will have stronger muscles now in the area of "getting in the flow" and this challenge is to learn how to do it even better. Perhaps the one thing that always increases in ease is remembering that it CAN become easier with practice.
I Still Don't Understand Why Being Present is So Hard
As babies, as you know, we are very very present - highly tuned to our every need, the sounds around us, tastes, touches. Everything is NEW too, and newness in this sense of novelty - like visiting a city for the first time - is definitely something that brings even the most jaded adults into a more present state of more joy.
So is it inevitable that as we grow up, and the novelty of things wears off, we leave the present because we are bored? That's one way of looking it.
But also as we grow up, we experience things that are not comfortable, and I believe it's these things that first trigger our impulse to leave the present moment. If managed property with guidance at an early age, you can learn to face painful things head on, let go, and move on to the next moment, fully present and whole.
But if you grow in an environment where you are inundated with modeling or messages that you are not worthy, then it's understandable why you would continue to leave the present and abandon your self. Living, mentally and emotionally outside the present moment, and essentially abandoning our needs in the now, is LEARNED and modeled for us by the people around us, who having gone through their own traumas developed ways of abandoning their selves to avoid discomfort and pain.
The irony of course is that it is the process of "avoiding" that actually causes the pain: the pain of self-abandonment. And as always, one of the best cures to changing this pattern is self-love, using meditation as a tool. There is no deep dark monster hiding in there that will jump out if you quiet your mind and sink into the present. The only "monster" there is is the voice that tells you you are not worthy, and which pulls you away from the moment.