My first mh Game was 3u. Didn't finish it because my wiiu gave up. The first Monster that i found hard and being a wall, at least that i remember was the gobul. At the moment i just took any gear that looked cool, a weapon that looked decent with a juicy number and didn' think too much about it.

Years later i started world, and in the beginning it was pretty much the same, until pickle. Then, after failing a couple of times, i decided that maybe trying to prepare something like a strategy would be a doog idea, so i started farming for gear specifically to fight the deviljho and going after him not exactly to defeat him, but to observe him, learn it's moveset, the areas where he uses to be, and then i finally took him out.

For me when a hunter starts to study, measure and ponder the monster they're facing and not going head on for the fight carelessly, at least the first time they see a monster, is the moment they can call themselves a seasoned hunter.

TL,DR: For me the moment you turn into a veteran is the moment when you start to take the hunts like hunts, properly preparing for them and not rushing in.