Fundamentally, retirement is about two things: bringing to fruition what we’ve learned and done earlier in our lives, and preparing ourselves to wrap up our own story, preferably on a positive note.

Relationships – whether intimate relationships, family connections, or friendships – are central to these purposes. We all can name old folks we have known who ended up lonely and bitter. It happens a lot, actually. But it doesn’t have to happen to you. Most of us also know people who lived into very old age surrounded by people who loved them.

By the time we retire, most of us have our major life accomplishments already behind us, but when it comes to how we relate to others, our opportunities to make a difference usually do not diminish at all. Even if old age eventually slows us down to the point where we have fewer connections, we can still make the most of those we have. And with the internet, we rarely need to lose touch with people, even if we can no longer see them in person – plus it offers unlimited opportunities to make new friends, even if we become shut-ins someday.

So our relationship skills continue to be important.

We can think of our relationships in three categories: existing relationships we want to maintain, old relationships that need repair, and new relationships. All three require focused effort.

Existing relationships are the easiest, but if we don’t put the effort in, we can still lose them. This is partly because all good relationships require ongoing attention, and partly because retirement itself (as well as the aging process) puts obstacles in the way. Leaving work means losing easy touch with long-time colleagues. Retirement sometimes also means moving to a new home, possibly with less easy access to old friends. Meanwhile, well into retirement, we might become less physically mobile, or we may be looking for ways to pinch pennies, and we can lose touch with people far away. And some of our friends will have problems on their end, so if we can’t make an extra effort, we’ll lose them.

We can even lose people close to home. Retirement changes our life, and so it changes us, and so it changes our relationships with others – with the biggest effect, often, on those closest to us. Retirement also, however, gives us time to reflect on, and to strengthen, our relationships with those nearby. We need to focus on others, when we retire, not just on ourselves and our own amusement.

There is also time in retirement to repair old relationships that have gone bad. This can be a tricky proposition, because both you and the other person have to perceive this as worthwhile and be in the right frame of mind for it. Not that every old friendship needs to be restored. But those that turned bitter, especially if they involve family, or former family, or other people you’re likely to have contact with from time to time, or those that just haunt you for some reason, or still make you angry years later – such relationships still have the power to drag you down, so fixing them (or at least attempting to) can pay off for you.

Sometimes forgiveness is all that’s needed. Not that forgiveness is always easy, or even always appropriate. And sometimes you need to forgive, and sometimes you are the one who needs to be forgiven. Either way, thinking hard about the relationship and what went wrong, trying to understand objectively how you might have made things worse, and how the other person’s point of view, even if clearly wrong, can be understood within the context of that person’s life, can be a first step. Give yourself time – any inclination to forgiveness must be real and lasting, not a passing whim. And when the moment is right, finally, reach out to the other person in whatever way seems most likely to be effective. Be prepared for rejection, regardless of who was at fault back in the day, since the other person is likely to be taken off-guard. But even if the re-connection fails, you can credit yourself with trying. And if you have achieved some real forgiveness in the process, and perhaps more understanding of yourself and how you relate to others, then you’ve still come out ahead. (For more about how to deal with such situations, click here.)

In particular, if you have a spouse or life partner, focus on that relationship. In any intimate relationship, there is always the need for forgiveness on both sides, because we have so many opportunities to hurt the other person, and inevitably we sometimes do, even if only inadvertantly. Likewise, gratitude is an essential virtue in close relationships – really in any relationship, but especially those closest to us, because it is so easy to take the other person for granted. In retirement, we can and should focus more on appreciating the many ways the other person makes our life better, and we should take the time to express how much it means to us.

Forming new relationships, finally, is at least as important as making the best of the old ones. As we age, we lose more and more of our old friends and family members, to death, disability, and distance. If we don’t replace some of those with new relationships, we risk ending up alone. In addition, if we don’t find ways to foster relationships with younger people – both family, and others – we can grow stale, and we also miss the opportunity to pass our experience and wisdom along to those who can benefit from it.

George Vaillant, the Harvard Univesity expert on long-term studies of people’s lives, has observed that the ability to connect with young people is one of the key attributes of those who age “successfully.” But this is a big topic, and perhaps we can return to it in more detail another time.

In the meantime, I want to leave you with this thought: establishing and maintaining relationships with other people is a skill and it requires effort. In retirement, we should take the opportunity to further develop that skill, and to put in that effort. When we were younger and busier, maybe we didn’t have time for all that. But now in retirement we do, and now is when it matters more than ever, since more than ever it is the people in our lives that will bring us opportunities for fulfillment and happiness.

Chuck Yanikoski is a retirement adviser who lives and works in Harvard. For more about him, or to contact him directly, visit www.ChuckYRetirement.com.