Here’s my Q&A column from the WSJ this week — and if you have any questions for me, you can tweet them to @danariely with the hashtag #askariely, post a comment on my Ask Ariely Facebook page, or email them to AskAriely@wsj.com.

___________________________________________________

Dear Dan,

I’m currently in physical therapy for a knee injury, but I haven’t been improving much lately. The main reason is that I’ve been slacking off with my exercises at home, which my physical therapist says are crucial for the treatment to be effective. I know I could be recovering much faster if I actually followed through with my exercises, but doing them is just miserable. What can I do?

—Jordan 

Because physical therapy is often tedious and uncomfortable, the mood to do your exercises will probably not strike you very frequently, if at all. What I would do is add something to the exercises that changes your motivation equation. For example, you could make a rule that your whole family can only watch their favorite TV show after you’ve completed your exercises. This way, the pressure of not wanting to disappoint everyone in your family will add to your motivation; and if you slack off, your family will nag you to get your exercises done. This approach can be thought of as “doing the right thing for the wrong reason”–in this case, doing your physical therapy in order to watch TV and not annoy your family. It is a great way to engineer our motivation to get us to do things that are no fun in themselves.

___________________________________________________

Hi Dan,

Recently, I retired on a small income. I have an old friend who visits regularly, and who is very well off. She often stays with me for a week or more, but rarely offers to cover any of the expenses connected with her visit, such as food or gas. She doesn’t take me out to dinner and seldom brings a gift. To make things worse, when we go shopping together she buys expensive things for herself, making the income difference between us even more obvious and painful.

I can get over the difference in wealth, but it is hard for me not to care that she doesn’t help out with expenses. How can I suggest that she chip in and still keep her as a good friend?

—Francis 

Since your friend is used to a pattern where you are paying for everything, she probably no longer thinks much about it. In general, we are all very good at taking things for granted. To break this pattern, I would sit with her over a glass of wine and tell her that while you love her visits, since you retired you feel a bit financially stressed. Tell her that you don’t want her to visit less often, but that you would like to alternate who pays for groceries and for going out.

I suggest alternating rather than splitting the bills because splitting requires an ongoing accounting, which is uncomfortable and can put an extra strain on the relationship. With this kind of an arrangement, the expenses won’t necessarily be divided equally, but it will help you avoid awkwardness during each and every transaction. My guess is that your friend will be delighted to share in the expenses, and you’ll wonder why you felt it was so difficult to bring this topic up in the first place.

___________________________________________________

Dear Dan,

Summer is here and I am wondering: what is the secret to a good vacation?

—Moran 

The first secret is not to call it a vacation. To vacate a place is to leave it, but the point of taking time off is not just to leave our lives behind. It is to approach something new and different. That’s why I think the British have it right: they call this time a holiday, which is a much more fitting name for an exciting experience. And since the words we use matter to how we think and act, my advice is: plan to have a holiday!

See the original article in the Wall Street Journal here.