I was told that idea and impression is different in a sense. So, what's the sense? I hope I remembered it quite well.
Idea is a state of mind that one may have over something/someone consisting of certain verifiable knowledge. On the other hand, impression is a state of mind over something/someone NOT consisting of verified knowledge but of mere personal biases due to culture, education, sex, religion, physical appearance, political history or other circumstantial facts.
Example of this is when one sees a shadow at night. That shadow may give an IMPRESSION of a male or a female - the thing is nobody can be so sure - thus, it cannot be a verified knowledge. Now, once that person appears, let's say it's really a man, then you now have an IDEA that that person and person's shadow was of a man (that man).
Another example maybe is when one is asked in a class recitation about a case that he has not read. In this situation, of course there is no idea. But, there is an impression. What impression is that? Simple. The case is relevant to the topic. That's it nothing more nothing less. But is case's relevance to the topic and the case itself the same thing? No. The case itself is the idea. If you don't know the case, there is no idea. If you only knew that the case is relevant to the topic, then that is an impression. You do not even know for sure that it is relevant until you have read it.
When asked, do you have an idea? If you really do not know and you are just to smile and say something cute, you only have an impression and not idea.
The common experience amongst us is when asked "what is your first impression" about somebody. Then we will say "akala ko dati suplada, pero nung kalaunan nakilala ko din at mabait naman pala". Take note the phrase "akala ko" (i thought). A person always have a first impression about somebody whom he really doesn't know. Whom he has no verified knowledge about. If this is the case, then you are freely and voluntarily creating your own impression. But once you've come to know that person, you will have realizations. You will have a verified knowledge. That's where the "akala ko" (i thought) sets in. When that happens, you start to form an idea. An idea which will last forever or at least longer than a mere first impression.
However, sometimes, first impressions are correct. But when will you know whether it is correct or verified? It will only happen after having understood that something/somebody beyond mere biases/impressions.
Let us then become holders of ideas not impressions. Verify important things or things that seem important to us in one way or another. Lovers of wisdom unite!