David, as a shepherd boy, had two hobbies:
- He learned how to wield his sling - by learning how to wield his sling, and by the help of God, he defeated Goliath.
- He learned how to play the harp - by learning to play the harp he won the favour of king Saul.
David did not waste his time while he was tending his sheep - he had his hobbies, things that God used to help David in the future.
Don't waste time. Have sidelines, things that you love to do, things that you believe the Lord has given to you to cultivate.