I think that information play and compartimentalisation is an important part of the game
unless all players including DM are OK with blatant metagaming about what monsters can do (I, personally, would not be). I think there should be a certain acceptance that certain common or memtic creatures will be known by the players in a vague sense (though generally I think characters that aren't worldly shouldn't automatically know, say, what a mimic is), but as someone going into GMing who does also want to play I feel that it's important to take into account:
- what I know my character knows;
- what I know as a player;
- what my GM knows my character knows that I don't know my character knows (and call tell me that off the bat);
- what my GM and I think my character might know that calls for a role (Survival, Arcana, Animal Handling, Perception etc. depending on what's being looked for);
- what my GM knows my character definitely doesn't know;
So, despite a lack of experience, I do get why after a certain amount of time, the contradiction between what a player knows about a common creature versus what the character knows about the creature can get very grating. But I think that act should be worth doing to both enhance roleplaying and lead to some fascinating moments. Imagine the roleplay you can get out of characters after figuring out fire is what stops that troll... and you have someone like, say, Caleb from Critical Role or the Hound from A Song of Ice and Fire in your party. Imagine the roleplay and character moments you can get out of that?