I went thru the same mid life rut as many of you describe. I had a "Is that all there is" tude. Then I read an article addressing mid life crisis. It said to think back when you were a small boy and had no limits on what you could think you could do. Is there a forgotten dream back then? In my case there was so I addressed it. Got to say it pulled me out of the rut with a new excitement about life.
I actually thought about it. It was my lifelong dream to become a firefighter and and EMT. I took the civil service test when I was in my 20's, scored well, but was put on a list. When my name came up I was not hired because the municipal department that chose me had a residency requirement, and I did not live in that town. I reapplied over the years at other departments but those with military experience and other qualifications were chosen over me. I've often thought a lot about going back to school to become a paramedic, but have been discouraged by most programs I talked to due to my age. They all say I would be considered an antique in that line of work. So, currently, I am exploring opportunities in other areas of the medical field. But choosing what to do is hard, I'm struggling coping with the financial burden it would place on my family if I were to quit my job and go back to school full-time. I secretly hope I'll get fired or laid off so I can justify going back to school. Unfortunately, my company has basically told me that due to my skill set, I'm not even close to the chopping block. I should be happy about this, most would be ecstatic, but for me, I'm like....."crap".
One of the reasons I got back into playing in bands was to "scratch the itch". I had been out of the game for a long time, and I remembered how much I loved playing. As my kids got bigger, there was more time. And I have had fun getting back in the game, but I'm not sure I'm as dedicated to it as my bandmates are. Getting home at 3 AM, then getting back up at 7 isn't as easy as it used to be. I really can see the day coming when I'm only interested in doing a jam band again, or a garage band, but that won't be for a while I think. It's still fun, but not as much as it used to be.
I've also thought about going back to playing hockey or taking martial arts classes. I did both extensively when I was younger. When I got married, I was teaching self defense classes two nights a week. But I was 23 at the time. I'd love to get back into it, but it's been a long time and the black belt has been collecting dust for about 15 years. And while I'm in decent shape, I'm not 23 anymore. And I've forgotten a lot. But this may be something I do starting this year. I started in martial arts when I was about 9 years old or so. I did it for a long time.
I have been kicking around the idea of writing a book. My wife has been encouraging me to try my hand at it for years. I think that may be my next venture. I already have an idea what it would be about. I just have to get off my duff and start it.
In any case, I have a lot of soul searching to do. I think I'm probably like a lot of people out there, though. It's funny, I look at my father. He's 65. No regrets. He's lived his life the way he wants to, and it's pretty obvious that he's a really happy guy.