I just turned 40 — here are 8 life lessons I wish I'd learned a decade ago

• Life lessons often only come with time and mistakes made.
• Figuring out financial responsibility, the importance of maintaining health, and having patience with my career would have helped me be more successful.
• Here are eight crucial life lessons that I wish someone had told me a decade ago.

When I was in my late 20s, my boss and I used to have epic lunches where we'd chat about life. One day, he told me that when you turn 30, you need to start being responsible. I didn't take him seriously, but now that I'm 40, I wish I had.

Here are eight of the hard-earned lessons I've learned leading up to my fortieth year that I wish someone had told me a decade ago:

SEE ALSO: The lesson I learned in my 30s that changed how I live my life

1. You may see some friends less often, but the bond remains strong

I've found that the closest friends I've had for the past 20 years are the ones from my fraternity — it truly is a forever bond. As life moves on, though, people do, too.

Some of your friends will move to different states, and some will get married, have kids, and end up immersed in a suburban bubble. Your inner circle will become smaller and smaller as you get older.

But that's not to say that the folks you see less often are gone forever. With many of my fraternity brothers, when we get together, we're still able to pick up right where we left off. It's like no time has passed. You just can't get bogged down with wondering when you’ll see them again or feel insecure about why they haven’t called.  

2. Your parents will need taking care of

My parents are on the verge of turning 70, and their health is becoming a concern. Between the two of them they have high cholesterol, hearing loss, and multiple medications, and doctor visits are becoming more and more frequent.

It's important to understand your family’s health and medical history, and to know all of their pertinent information so you can handle any medical situation that may arise.

3. An extravagant wedding is overrated

If there was ever a moment where the idiom "If I knew then what I know now" fits into this post, it pertains to my wedding. Yes, it was beautiful – everyone we wanted was there, we had an outdoor ceremony, the music was amazing, and the caterer's pigs-in-a-blanket were hand-rolled!

But weddings can be uber-expensive, especially in the New York City area. Planning a wedding often causes stress for the bride and groom and strife among the parents paying for it.

If you really want to have a wedding, focus on curating your guest list, paring it down only to the folks who must be there. Do what I would do now if I had the chance to do it all again: Take a long and lovely honeymoon and start your life together without this nuptial nonsense.