If ever you have been cross with someone because you were angry about something else, you have no right to expect to be treated kindly and politely by others.
If ever you showed no mercy to someone who would have welcomed mercy, you have no right to mercy when you wish it.
If ever you found yourself unable to forgive someone who truly regretted what they had done, you have no right to expect forgiveness when you want it.
If ever you denied your company to someone who needed it, your own loneliness is what you have earned.
In other words, what you have reaped is probably exactly what you have sown.