Please forgive this example.
Remember the like dissolves like rule in chemistry. For example, polar compounds tend to dissolve other polar compounds. And non-polar compounds tend to dissolve other non-polar compounds.
Here comes the weird part. Imagine a long hall filled with voters. Two candidates, one from each party and running for election, must go through the hall. Both candidates want to get home as soon as possible.
We will have both candidates, one republican and one democratic, enter the hall at same time. We'll stack the voters in the hall. All of the voters in the hall will be from one party (say democratic). Which candidate will leave the hall first?
Usually, the republican candidate will leave the hall first. He won't have as much in common with the voters. They won't talk as long. So he will be able to exit the hall first.
On the other hand, the democrat candidate will have a lot in common with all the voters. He will talk longer to them and talk to more of them. He will stay in the hall longer and exit much later.
Replace the candidates with polar and non-polar compounds. The long hall is the GC column stuffed with a polar compound.
You have many thousands of interactions. The compound will travel in the gas, meet one of the voters (chemical molecule), shake hands (be somewhat retained), go back into solution in the gas, travel to the next voter (chemical molecule) and slightly retained, and so on and so on.
The other compound won't shake hands with the voters and will travel through the column very quickly.
Stupid example, but hopefully it will help you visualize the process.