I think reaching 1400 elo after a year of decent study after learning the rules is not too unreasonable. To reach 1400 in a year you would need to be either talented or hard-working. Climbing the elo ladder does get much harder though, as you mentioned. To reach 2000 in two years you would need to be both hard-working and talented. To reach 2850 in a lifetime you have to be hard-working, talented, and a particular Norwegian GM.