Many years back, when I was a university student, I used to conduct one-on-one tuition for school children. I knew several people in the business, and we often made referrals for each other. Once an acquaintance was approached to give tuition in a subject he hadn't specialised in, and he contacted me since I had. What he didn't tell me (and I was naive not to ask) was that he had collected payment for that month. I tried to reach him severally but somehow we never got together. But that isn't why I am writing this.
What was remarkable about the situation is that when he needed to find me having promised his client (he was giving tuition in other subjects) that he would, he did everything possible to find me. In fact he turned up at my house one morning before 6.30am, to catch me before I left for the day. (It was before mobile phones came easy). Yet when it came to sharing the spoils, it was another story.
This situation repeats itself in many other interactions. A friend borrows your car, but when it is involved in an accident you are chasing after documentation alone. A relative borrows your book, then lends it to a friend and complains when you insist they get it back or buy another. A colleague borrows money because they don't have change, and you don't see it again.
Of course, you can ask for your belongings back, or demand that the borrower meet the cost of any damage to your car...but you don't have the heart for it, and you are afraid of the fall out. Yet, this thing can stand between you for ages, and may lead to that fall out anyway.
How to avoid it? Be clear about the 'terms of reference' before you lend out your car or book. Let the other person know what you expect from them in relation to your property. If it is the money for change, ask them to give it back before you go home that day, and remember to ask before you leave.
While this will not stop any event as described above, it sets the stage for a subsequent conversation should there be need for one. And if you are particularly finicky about something, don't lend it out. It pays to know who is on the other side before you open the door!