I turn 40 in about an hour.

Here's a thread about some things I've learned over the years and some of the major differences I've noticed between being 20 and 40.

When I was 20, I thought older people were all more intelligent than me. That's not true at all.

It depends how you define smarts, but using something like IQ, you can be smarter at 20 than anyone else.

Wisdom and experience are the real advantages that come with age.

Mentally I don't really feel any different now.

I still have essentially the same interests, ideas, passions, desires, and thought processes as I did when I was 20.

Physically it's a different story.

The biggest thing I took for granted, and one thing I would love to have back, is stamina.

I could run up and down a basketball court for hours, take a dinner break, then play tennis for a couple more hours.

Then spend the rest of the night doing homework or studying.

Now I play 2 hours of tennis or work out for 45 minutes and I'm basically done for the night.

Except for wisdom, I think I would trade anything else to have that level of endurance back.

One thing you have to experience to believe is just how long it takes to recover from injuries at this age.

At 20, I could beat a sprained ankle in about 3 days.

At 40, a sprained ankle could mean no sports for a couple weeks, and maybe even longer for a full recovery.

In March I got some shit called elbow bursitis. I had never heard of this before and had to Google it.

Well, the swelling disappeared in about a week, but to this day there's still pain when I put pressure on the elbow.

And that was THREE MONTHS AGO.

It also takes a lot longer to warm up your body when it comes to sports and working out.

If you're like me, you will constantly forget this, but after you pull a back muscle a few times, you'll learn to start stretching beforehand.

That ties back to wisdom and experience.

You can still play a sport at nearly the same level as you did when you were 20, but not for as long, and not as consistently over many days.

This is why Federer can still win matches vs. youngsters, but throw in a random clunker that will make you think he's done for good.

If there's anything you really want to do (travel, start a business, etc.), I would say do it NOW.

You think you have all this time when you are young, but you end up saying, "I'll do X in a few years", and before you know it 10 years have passed and you still haven't done it.

And everything is more difficult when you are settled down in life.

For example, I've always wanted to visit Australia and Japan.

At 20 this would be easy. But now I would have to work around my girlfriend's schedule, find someone to watch the dogs, etc.

And my body doesn't handle flying as well at this age, so a 14-hour flight is no joke.

Not to mention something like a global pandemic can occur and completely shut down the world for months or maybe years.

No amount of money or wisdom can give you time back.