I have always been good at staying in touch with people. Former classmates, teammates and even co-workers.

Part of this is because I am friendly by nature. I am the type of person who will stop to say hi and chat if I cross paths with someone I knew from 20 years earlier. My memory could rival an elephant, so I can often bring up old stories or jokes or mutual friends and we can share a laugh together.

With very few exceptions, it is almost always a good idea to stay in touch with someone from your past. (Former romantic partners, people who are negative influences on you and Montreal Canadiens fans would be some of the exceptions).

In today’s day and age, social media has made it easy to stay connected. Even if you don’t engage directly with someone, you can often see major life updates through Facebook, Instagram, LinkedIn and whatever other socials people are using.

Staying in touch with former colleagues can be one of the most valuable, long-term investments you make in your career — and even your personal life. I organize former co-workers into tiers:

Tier 1 – The friend: Those who have become friends you met through work. These are the people that you might have met at work, but that is not why you are friends. You can chat about work stuff, but you can also talk about sports, family, world events, etc. You likely share common interests and probably spend time together outside the office.

Tier 2 – The work friend: You might not have become friends if you weren’t working together 40-plus hours per week, but you get along well and generally enjoy their company.

Tier 3 – The colleague: People at your workplace who you don’t interact with frequently. The interactions are usually pleasant and polite but neither of you go out of your way to really get to know one another.

Tier 4 – The difficult co-worker: Someone you butt heads with, rarely see eye to eye with, and in general don’t have a lot of time for. Hopefully there aren’t many of these at your workplace (or that might explain why they are now former co-workers).

You should definitely stay in touch with the top three tiers; sometimes it makes sense to stay in touch with Tier 4 contacts. I have one friend who hired his ex-wife for a role because he knows her work ethic and product knowledge (and four years later they are still working in relative harmony).

A significant number of job opportunities or business opportunities come through referrals and recommendations. Your former co-workers are more likely to recommend you for positions or connect you with someone in their network if you’ve stayed in touch and they remember how you treated them.

It’s not just about who you know — it’s about who remembers you and how you maintained the relationship after parting ways. This has really helped me out in the sales world, as my former co-workers are now working for potential customers. It has also helped me recommend former co-workers for jobs and provide introductions to business opportunities.

The transportation world is small and huge at the same time. You never know when your paths might cross again. Former co-workers may become future business partners, clients, collaborators, or even employers.

Staying in touch increases the likelihood of organic, mutually beneficial opportunities down the line. The professional world is smaller than it seems, and positive past relationships can lead to unexpected partnerships.

Sometimes, former coworkers become lifelong friends. They’ve seen you through tough deadlines, stressful meetings, and career highs and lows. These people often end up being trusted confidants, offering a unique blend of personal and professional support. Staying in touch helps maintain those relationships, which can be just as important emotionally as they are career-wise.

There really aren’t many reasons as to why you shouldn’t stay in contact with former co-workers. If you got along with someone and enjoyed the conversations and jokes, that does not need to be confined to the office building. These are people who were part of your journey. Don’t let the shared history fade — nurture it, and it may pay off in ways you never expected.