It's ok to be a couch potato for one day.  As a matter of fact it is good to do it.  It feels good to not go outside one day and instead cuddle up inside with a good book or just catch up with your favorite TV shows and do absolutely nothing.  Order take-out, better yet: delivery.
It's ok to skip the playground for once and instead take him/her to a fancy restaurant where he can learn cool and sophisticated words such as 'Pappardelle' and 'Meunière'.

It's ok to not get your manicure done one week and instead spend more uninterrupted time with your loved ones.  You can always get your nails done any day but family time is priceless.

It's ok to go back and rewrite one or two of your new-year resolutions.  More realistic and approachable goals will make you happier and most importantly you get more results when you focus on the day by day action when compared to a deadline.

It's ok to say no because you simply don't like the idea.  Just remember to be nice.
It's ok to not worry about dating for once.  Enjoy your single life, make lots of friends, travel, make lots of mistakes.  It took Edison 10,000 fail errors to come up with the electric bulb.  Mistakes are the only path to learn.