How do you feel about the fundamentals of whatever art you practice? Have you gotten to the point that you are confident in your ability to apply the beginner-level stuff? In aikido, have you got release #1 and shomenate down pat? In judo, is deashibarai and bridge&roll escape from kesagatame old hat? Are your jodo kihon and kenjutsu suburi so perfectly polished that they bore you to death?
If so, you definitely need more practice, because you do not have it yet!
I've now been doing martial arts for about 26 years and aikido and judo for about 22 years. I've been teaching these arts for around 16 years and have gotten some of my students as high as sandan (3rd degree black belt). Other instructors occasionally tell me that I'm passable good.
But the most basic stuff still perplexes me every single day. The more I learn, the more I find that I have yet to learn. There are just so many facets of every single step - so many rabbit holes...
I'm beginning to think I'm going to have to live to be 200 years old!
Photo courtesy of Ryusinkan.ru