Now I know.

For fun Friday night cleaning, open bottle of wine and have a glass or two while pulling bed away from wall, gasping at mounds of dog hair and running to get the vacuum cleaner with attachments. However, having three glasses before deciding to rearrange bedroom furniture may result in curious bruises the next morning.

Never switch from Asics stability to Brooks motion control shoes mid-training. Instead, replace worn out Asics with a fresh pair, which, in the long run, saves money and injury and mental stability.

To get best fit, wear running singlet when trying on a water fuel belt at the running shoe store. A baggy T-shirt will result in a belt that’s too big, which will be uncomfortable and bulky and heavy and won’t do you any good when it gets stashed in random bushes at mile 2.

Do stash water bottles along route of long run. Don’t worry what random people think when you pull up to corners in your bright red car, jump out of the car with a bottle of water, run up to some bushes, hide the water, jump back into your car and take off. They’d understand if they were distance runners, too.

After the first 6 of a 9 mile run, legs begin to feel like lead. Do have headphones with Walkman for this occasion — nothing like a little Coldplay to get back into stride.

Don’t use walkman with headphones when running alone, which basically targets you for attack. Instead, take running buddies, too.

It’s a good idea to shop organic and to eat healthfully. It’s probably not a good idea to stand at the meat counter at Whole Foods, gasp and proclaim for all to hear “$8.99 for a pound of chicken breasts? I only pay $1.99 at Price Chopper.”

It’s not 1996. Don’t fool yourself into watching the MTV Music Video Awards because you will not know 2/3 of the people winning the awards and you will wonder when hip-hop took over the world. And if you have to watch one more minute of that R.Kelly mini-series thing, you will most likely lose all faith in humanity.