75 years? long ? short ? Haha this is the subject for me.
That's it. All depends what are your life plans exactly and you expectations. To make it easier I'd say there are just 2 groups of people.(examples have nothing to do with making big money - it's just pathetic thing to plan life for)
GROUP A[/b] - If you plan to finish basic schools, have some regular kind of job (like without passion just money for life) and later in the evenings, on weekends just hang out with friends, and have only fun, play games - in this case - 75 years can be long enough. You can get bored before turning 50 - and finally die bored as hell :) Bored of yourself mostly.
GROUP B - But if you plan to have nice family, some university degrees, want to pass your knowledge to others, have some little invention of yours patented, produce few albums of your music (no commercial stuff), make at least few own movies with original storyline, travel for few years to meet few culture, adapt there and meet interesting people to talk with. Help a bunch of people in their life, let them develop some of their things also. And finally - after all that play - new amazing games of 2020, 2030, 3040. With new gaming technology and different ways of enjoying them - like today's simple Omni, Oculus Rift and others we can only dream about in next 30 - 40 years. Also build at least one or two own games of your dreams - which you always wanted to create.
If you plan to do those all little things - 75 years is nothing. It won't be enough for sure. Why ?
Because (and this is the fact) first 25 years of life is just a starter. It's just a base when you work to have basic things done. The base on which you can really start to build all your adult life the way you always wanted. So finally we have only 50 years to do all these things :)
Yes 50 years still may seem a lot - but if you take away 50% of that time for sleep, basic work, shopping, driving in traffics, being sick, fixing things in house, renovations of your flat, preparing stuff and other 100% not useful things at all - which have completely nothing to do with your real life plays - we would have only 25 years left - and really - 25 years is not much at all. It can pass by very, very fast with tv remote control in one hand and beer in another - the way it works for most of lazy people unfortunately :)
So 75 is a lot and not enough at the same time.
I'm afraid I'm in that second group (B) of life planers :) and I know I will never be able to do 100% of those things that I wanted (and I really didn't want so much as you saw comparing to some crazy plans people have). So I'm trying to focus at least on 50% of those things right now. I think those 25 years will be enough for half of my plans :) 50% will be just fine for me.
The problem here is - that even for few those little things we need to have very good schedule. Without wasting many years and simply losing energy and 40-80 hours a week just for pure, unproductive fun ;) That's also why I'm only a player now - not a gamer anymore (give me 36 hours long day/night cycle and I will be the one. I would love it).
I was real SP gamer between 10th and 15th year of my life though. Fortunately I was able to ended this "dark" period in late 90's ;) and start using computers for more creative things.
Productivity over Consumption! This choice that you won't ever regret after years :)