the basic assumption behind all training systems is that if you do the work you will get better. and as a coach I do truly believe that everyone can improve to a level at which they can enjoy being competitive. that doesn't mean that everyone can go to the Olympics, it means you are not fated to always be at the back of the field in your local 5km road races or in open 1500m or whatever it is you want to do.
there has been a debate for a very longtime about how much of what you achieve is due to innate talent and how much is due to training. Herb Elliott, for example, worked hard, but he was also a highly talented individual, as also was Jim Ryun, so the work they did complemented their talent and they became very successfull as a result of that fortunate complementary coincidence.
by contrast, I personally do not think Steve Prefontaine was a hugely talented guy, at least not at the sport he chose, but he worked his ass off at it to become the best he could possibly be and as a consequence he more than deserves the almost legendary status he has in some running circles.
take Tiger Woods, for example. massive talent at golf, but had he chosen some other field, baseball, for example, he might not have succeeded to the same degree, so there is an element of luck in choosing the sport that you are naturally talented at. many people choose things they enjoy but at which they are not naturally talented and for which they are not particularly suited. my next door neighbour, unfortunately, plays the piano for that exact reason and I often find myself wishing he had taken up the triangle instead.
the answer to your question, then, is that it doesn't matter whether you have talent. 8:19 for 3km is a really good time and you deserve to be congratulated for that, which is actually what you came here for, but I hope you will not stop there and will use the progress you have made as a springboard to better things. laurels are not made for resting on.