It's such a temptation to get ahead of God sometimes. Not that we do it intentionally, but we are so eager for the next step or the next season and what we can accomplish there. Which causes us to focus less on where we're at right now.
When we're single, it might be something like "When I get married life will finally start...then life will really be important...I'll be happy, fulfilled, etc.". But we're so busy trying to plan for and get to the next thing in life, that we're missing out on the amazing, one-of-a-kind opportunity that we have to serve God in our time of singleness.
Then when we do get married, we can think that "As soon as I have kids, then I'll have another experience under my belt and I'll be able to minister better...or I'll be closer to what God has for me, etc.".
But then we get restless again, and we're looking at all the things that we can't do and we think "I just can't be as involved with serving and ministering in the church and out, because I have so many little children...once they get older then I'll be able to do more."
But we miss it it again. Because we're so caught up looking for the more important thing and God is just waiting for us catch on and realize that He has us where we're at for a reason. His plans are not without purpose. If only we would truly trust in that.
We need to just slow down and enjoy each season of life, focusing on where we are at this moment, and how we can glorify God while we're here. We need to stop believing Satan's lies that we would be more valuable if we were in another season of life. Learning to be content brings great joy. Not that I have it mastered, but by God's grace I'm learning!
"For I have learned in whatever situation I am to be content. - Philippians 4:11