I agree with esshup that experience will definitely help with your ID ability.
I will add that human brains have an amazing capacity for "pattern recognition". If you watch the fish off your dock or shoreline for 10-15 minutes, then I expect your ID ability will improve even during that short time window.
I was recently at a friend's pond watching the tilapia hanging out among his other fish. I said that they looked like SMB in the water to me. However, after 10 minutes of observing them at many different angles, and motions through the water, and the way they held themselves when they were just hanging in the water, my brain began readily identifying the tilapia. It became so clear what they were, that I kind of couldn't believe that I couldn't see it before!
I think our brains can easily take hundreds or thousands of "snapshots" of the fish in the water and then integrate that data into a whole, easily identified fish that gets plugged into our memory.
In the future, you will probably be able to glance down at your shallow water and your eyes will send your brain a "snapshot" view of three fish in the water, and your brain will instantly go - LMB, LMB, tilapia.
