Listen to the lyrics closely and play it about 6 times in a row. There's some wisdom in here, and it's a good tune besides, with the well-known three-part harmonies of Crosby, Stills and Nash.
It's the kind of song that all adults can appreciate on some level, with the benefit of hindsight and experience and all the things we wish we had done differently, way back when.
Back in the 90s I remember playing the cassette with this song on it, and playing this song on repeat, over, and over, and over again ... something about it just hit me hard. Regrets, we've all got 'em, but we have to be careful not to let them run our lives. It's tricky sometimes.
Here's a live version: