This is an analogy that I sometimes use. If you are learning to do multiplication and the first examples are 10, 100, or 1000 times some number, do you need to learn to do multicolumn multiplication or can you just add the zeros? Organic chemistry can be like that. Why learn to multiply when all you need to do is add the zeros? Why learn the mechanism if you know the products?
So if they give you a multiplication problem and they ask you to multiply by 1100, can you do it? Will knowing how a reaction takes place get in the way? For me, a mechanism is the chemistry. It is simply an explanation of why a reaction leads to a given product.
In my classes, I focussed on reaction mechanisms. By doing so, I was able to raise my class average by over
20 percentile points on the ACS organic chemistry exam.
I don't know anyone who is a serious organic chemist that doesn't know reaction mechanisms. In my industrial career, I relied completely on the reaction mechanisms that I first learned as an undergraduate. Reaction mechanisms are fundamental to organic synthesis.
While I do believe that learning reaction mechanisms is the best way to learn organic chemistry, I also understand the opinion of others who would disagree. Many (most?) professors pay lip service to mechanisms. Many of them do not believe that students can even learn them, therefore they avoid reliance on tests that require mechanistic knowledge (are old tests posted and they are similar?). In that case, it would be asking a student to go beyond what a professor is asking. However, if you are beginning to become confused by the variety of reagents and products that may form, it is because memorization is not a substitute for knowledge. Students that know the mechanisms generally do not suffer this same confusion.