It's not any easy art to learn. I doubt I will ever say that I've mastered any part of it. Every time we have a class, even the most basic techniques have layers of complexity hidden within the apparent simplicity.
I started late in life, I'm not flexible, I'm not coordinated. I haven't been in any sort of fight since I was a kid. The likelihood I will use Aikido in a self defense situation seems very small. And learning Aikido so you can beat up bozos makes no sense at all.
So why? One answer is framed and mounted on the wall of the dojo.
"Let us have a Universal spirit that loves and protects all creation and helps all things grow and develop. To unify mind and body, and become one with the universe is the ultimate purpose of my study."
-- Koichi Tohei Sensei