We all change with time. Those clothes we wore as teenagers may not fit anymore, or may seem wildly inappropriate.

In the 1970s, I actually bought a pair of platform shoes, which for some unknown reason were fashionable at the time for young men. I didn't wear them much, and I don't even remember getting rid of them. (Man, I hope I still don't have them stored in a box somewhere!)

Other things I have from the past I have kept and still prize. I still love the pair of sweaters I got in South America some 30 years ago.

While people certainly are not articles of clothing or shoes, friends can in some way reflect these same points. I am in touch with relatively few friends from my youth. Sometimes that seems sad, but then I realize that I was actually a different person, as were they. That has happened even with some of my best friends from years ago.

I have deep bonds with a few friends that have stood the test of time. We both may have changed, but our values are still similar. In many cases, I'm better friends with them than I was years ago. I consider them friends for life. They are like family-and, to tell the truth, I'm closer to them than I am with much of my family.

We run into people over our lifetimes with whom we are close for a while. Then time and distance wear at the bonds and sometimes dissolve them. That is a little sad, but I try to appreciate the friendship we had. After all, not even life is permanent.

Social media, for all its ills, and other forms of communication via computer do help us stay in touch with friends and acquaintances. It is especially helpful for those of us who have moved a lot, even to the point of changing the continent where we live. After moving to China over eight years ago, I discovered a wonderful new world and made new friends, but I haven't totally lost touch with people in other places.

Still, it takes effort to maintain a friendship-the proverbial twoway street. That means more than an annual birthday greeting. Not all the friends you've made may be willing to participate. But for those who are, it's a chance to build on the friendship you formed-adding layers, exchanging new experiences and, if you're lucky, getting to see them in person again. (Though, in most of the world, this last thing may have to wait on more success against COVID-19.)

Here's a few of the tips on maintaining your relationships found online at getthefriendsyouwant.com.

1. Keep taking an interest in what they do. Share your own interests. If they pick up a new interest or hobby, get excited and be happy for them.

2. Stay in touch. This is 80 percent of the game in maintaining friendships.

3. Reciprocate a friend's interest. If they reach out or share information with you, do the same.

4. Manage conflicts; it's the best of friendships that are likely to hit a bump in the road. If you don't, you might lose a dear friend.

5. Remember that your friends will change, as will you. The most interesting of your friends are those who seek out new things.

Other bits of advice: Be more open, go easy on criticisms and keep secrets.

Good friends are like gold. Over time, I've learned that it's worth the effort to keep them.