With comfort comes complacency, and with complacency comes problems
Have you ever gotten so comfortable with something that you stopped practicing the basics? What happened? My guess is that you ran into problems!
This is what happens when people get too cocky and think they can't lose, someone else comes along, puts in the effort, and blows them away. This is how careers fail after years of success, and how relationships die after years of marriage. We get lazy and start taking shortcuts.
Just remember, with comfort comes complacency, and with complacency comes problems. Don't get so comfortable that you start thinking you can stop practicing the habits that got you to where you are today. Do that long enough, and you'll be sitting on the side of the road wondering what happened.
If you've wandered off track in your career, relationships, or any other area of your life, all is not lost, although you may have to start over depending on how far you've let things slide. Go back to the beginning when things started working for you, step up and start doing those small things again consistently, and you'll be amazed at how quickly things can turn around. Good luck!