Not at all! See, there’s some expanded rules about “naming” a card, and all you really have to do is uniquely identify a card. That means you need to give sufficient information that only one card could possibly match the description you’re giving. If you’re having trouble with this, you can call a Judge over and have them help you with this! For example, “The 3 mana jace from Ixalan” is sufficient information to name Jace, Cunning Castaway. It is the only 3 mana Jace from the Ixalan set, so that description could not match any other card. However, if you were playing in Modern and said “The three mana Jace”, that wouldn’t be good enough because that could be Cunning Castaway or Jace Beleren– so you haven’t uniquely identified a single card yet. In that case, the Judge would probably ask you to clarify further. It’s easiest when you know the exact name you’re going for, of course, but don’t feel bad if you can’t remember the exact name! Just give the best description of the card that you can, and you should be fine. “The new Rakdos that flips coins and blows up the board” is fine for Rakdos, the Showstopper, and “the Boros creature that costs RRWW” is sufficient to name Truefire Mentor. If you can’t remember the name, just give as many details as you can remember, and you’ll be okay.