How long/much does it take to be a consistent winner?

[ticks]

Im relatively new to holdem(and the forums),
been playing online for 4-5 months.
Mostly limit, but more and more NL.
Lately I've been wondering:
How long did it take for you to be a consistent winner?
(at low limit NL)
And how much did it cost you?

Im sure im not the only one wondering about this,
would be nice to have some sort of average yardstick to measure yourself against