I've been pondering this for some time, and it seems that there is a common thread.
I can only speak for myself, and my story is that I'm 42, married for 6 years to a great lass, have a 5 yr old girl and one on the way in 2.5 months time.
I've always wanted to travel, but my wife is completely disinterested in biking generally and does not understand my desire to tune and rebuild bikes in the garage. At all.
In 4 weeks I'm going off with my brother for 2.5 weeks on a UK road trip from Denmark (GPz 550 tour I wrote about on this HUBB), me on my bike, and my brother on the one I rebuilt for him.
My wife is taking it a bit personally, and cannot understand why I would want to be away from them for this time, and does not understand that it's not about getting away from them, but rather the trip itself. She has, however, accepted this and said "I think you should go". I wasn't awaiting approval, but it came nevertheless. Bonus.
I will miss them, but it will be ok! We'll stay in touch every day and I'll try to make it fun for my little girl too, but I know that if I don't go ahead, I'll regret this and I'm not prepared to do this.
There will be other compensations I will make for my wife in time, such as going to OZ for 3-6 months to baby sit the new arrival and care for our daughter whilst she continues with PhD research at a hospital in Sydney, so it's swings and roundabouts. There has to be some give and take if your partner is not interested in your business.
I say, do what you need to in this life, as it's too short to pass by with regrets, but think of ways in which you can accommodate the other at the same time as their desires are also to be met.
It's hard though to convince the other half of those inner desires that perhaps were not written on the sleeve of your jacket when you were walking down the aisle all those years ago.... my wife had no idea THEN that I was so into mechanics in general, as when I met her I was living in a bedsit in the UK and had no access to a garage, but had lived on the wild side in South Africa in the biking scene for some years, and that never dies.
Now there's no room in the garage for her car with all the bikes in the way... oops.
Every family is different. Every woman is different. It's about communication and finding the balance. (Sometimes in between my own selfishness)
In my case, 2 weeks for a trip was the pain threshhold, so I stretched it to 18 days. I cannot get more or the elastic will snap. If I took a month there would be serious problems, which would describe what some folks here have gone through, and I'd prefer to keep my family in one piece because at the end of the day, If I had to choose between my family and my biking, I'd sell the bikes and live with that lesser regret, as my family come first.
I just like pushing the boundaries I guess, but at the same time, life is for living. This balance is an interesting debate.
It's about prioritizing passions.