Wow, 2 years! That was my first thought when realizing I had been taking Krav Maga for that long. It's a good amount of time. I should definitely be lethal by now, right? Probably, but the more you train the more you realize the different ways a fight can go sideways and how many situations you've never thought of. That being said, my confidence has never been better and my physical and mental stamina have significantly improved.
