This is a great point, and one that is not made enough. I consider myself a fairly intelligent person, a hard worker, and yet I definitely have had my share of learning bumps trading. Before I ever started, I think I read almost every book out there, spent literally hundreds of hours back testing and modeling, and months paper trading.
Thought I had it down, dived in with about $20K of my own money. It was gone ten trades later. Started over, developed a strategy that seemed to work spectacularly, eased into it -- but did not REALLY understand how volatility impacts options. Had great returns for six months, then things went hay wire and I loss half of my money and half of a family members money that I was given. (That was hard to deal with personally -- I can deal with learning bumps/failures myself -- I DONT like hurting others, particularly family members. I know investments are a risk, but its different when YOU are the one losing the money for someone else).
Flash forward six or seven years, and I finally feel like I know what I'm doing and am making good returns. Yet I still learn something new almost every month.
It is GROSSLY unreasonable to expect to make 100% returns yearly -- EVER. It's particularly unreasonable to expect it right out of the gate. Not impossible, just unreasonable.