I know I've talked about this before, but I feel like it bears repeating.
So often I hear singles lament about being single, but then I watch them live a completely self-centered life. It's all about them!
If you really desire to get married and you want to have a satisfying marriage then you must practice selflessness in your single years. You won't just be able to switch that selfishness off. It will be there, larking in the corner. You'll feel entitled to "me" time and you'll be discontent with when marriage and/or parenthood seems to demand your everything!
Philippians 2:3-4: Do nothing out of selfish ambition or vain conceit, but in humility consider others better than yourselves. Each of you should look not only to your own interests, but also to the interests of others