“If you knew the time it took me to gain my mastery, it wouldn’t seem so wonderful.” – Michelangelo
The simple answer is “yes”. A year in Karate/Tae Kwon Do/Kempo and you can probably fight much better than before. It takes well over a year before you start feeling comfortable enough with Aikido techniques to imagine using them in “real life”.
The complex answer is “no” in the sense that I don’t think anyone ever feels like they have “mastered” an art. If they do then they’ve stopped growing, or the art is too simple.
An old story might tell you some of the mindset you ought to apply when studying martial arts:
A young boy traveled across Japan to the school of a famous martial artist. When he arrived at the dojo he was given an audience by the sensei.
“What do you wish from me?” the master asked.
“I wish to be your student and become the finest karateka in the land,” the boy replied. “How long must I study?”
“Ten years at least,” the master answered.
“Ten years is a long time,” said the boy. “What if I studied twice as hard as all your other students?”
“Twenty years,” replied the master.
“Twenty years! What if I practice day and night with all my effort?”
“Thirty years,” was the master’s reply.
“How is it that each time I say I will work harder, you tell me that it will take longer?” the boy asked.
“The answer is clear. When one eye is fixed upon your destination, there is only one eye left with which to find the Way.”