There are some people who pride themselves on being "original" thinkers. This can be GREAT! Part and parcel of learning Torah is being MECHADESH in Torah. The PROBLEM is when one's originality veers outside of what is acceptable - the 71st face of Torah, beyond the pale. One must remain with his faith in the Chachomim and their wisdom and their traditions and not invent radical ideas that have no basis in fact, reason or tradition. [There are numerous well known examples of this in our time].
In addition, one must also review things he already knows because there he will find new gems, as the gemara says on the pasuk אם שמוע תשמע - אם שמע בישן תשמע בחדש - If you hear the old, then you will hear the new. Paradoxically, chiddush flows often from what one already knows, when he revisits the topic.