When I was 11, my sister bought our father a ''World Greatest Dad's'' coffee mug, and frankly, the man coasted until the day he died.
This sentence comes from a piece of line of Sheldon in The Big Bang Theory. The meaning of coast as a intransitive verb below, and pls interpret it in this particular context above.
1.to slide on a sled down a snowy or icy hillside or incline.
2.to descend a hill or the like, as on a bicycle, without using pedals.
3.to continue to move or advance after effort has ceased; keep going on acquired momentum: We cut off the car engine and coasted for a while.
4.to advance or proceed with little or no effort, especially owing to one's actual or former assets, as wealth, position, or name, or those of another: The actor coasted to stardom on his father's name.
5.to sail along, or call at the various ports of, a coast.
6.Obsolete. to proceed in a roundabout way.
All the listed definitions are quoted from Dictionary.com