How would this work?

Cards that have effects such as: If you activate this effect you cannot declare an attack this turn.

If I used a card, say Forbidden Lance for example, would I still be able to attack with a monster I control? I'm pretty sure that I'm not as the first effect enables ME to declare an attack, not my monster, so the monsters aren't even affected in the first place? But I'd just like to double check.

I am almost 100% sure you still cannot attack. As it is a condition, not an effect.

(Vantage) Looked up rulings, still unable to attack. Thanks.