Hard work can be draining, leaving you exhausted, negative and wishing you could do anything else. This hard work feeling typically comes from work that does not seem significant, relevant or worthwhile. It can seem like thankless hard work.
On the other hand, hard work can motivate and inspire. It can be a stepping stone to greatness. It can take you to new places, leaving you wanting to see more, regardless of how hard you will need to work to get there.
Find your passion and let it fuel your work. You will find that the hard work hardly feels like work at all.