I agree with many of the points made by R.L., Gary, and J.
J makes some very good points about the distances involved in exploring the stars. It is quite clear that propulsion is not the key to interstellar travel. As stated, even at the speed of light, a person would be elderly after having only explored a fraction of a single galaxy.
The key to interstellar travel is a greater understanding of topics like space time, dark energy, and gravity.
Hopefully, with time, good people, good science, and a bit of luck; our ancestors will not sneer, but look back on us as scientists who laid the foundation for their work. I believe they will praise our desire for knowledge, and praise our quest to reach out beyond this small blue planet in the Milky Way.
As Nick Hoffman famously said - "The universe is and does as it wants, not as you or I want."
Vince