Actually, if you run the numbers (there are web calculators for such things), a trip to Alpha Centauri and back would take you 7 years. "Everybody you left on Earth" would have aged only about 15 years.
The presumption, and yes, I know it's a big one, it requires you to travel with constant-acceleration engine(s) for significant times to speed-up, slow-down for an AC "visit", speed-up for return, and slow-down for re-entry. Also, there is a presumption of a very short AC visit... add more time for the desired length of stay.
Alpha Centauri is 4.22 light years from Earth. A single light is around six trillion miles. If you intend on coming back you’d have to square that distance. That’s going to be a lot longer, either way then just 7 years.
I did a paradigm shift a few years ago, regarding interstellar travel. That is, all interstellar trips would be, for all intents and purposes, one way trips.
That’s assuming we don’t figure out some faster than light, space folding, warp drive or other methodology for making it a quick trip.