It's doable but you need investment skills. 5% after inflation is likely pie in sky for most people. You need a lot more nest egg in the current low interest rate environment. Also at 35 you will still need money to put children through college so the future expense is likely higher than your past experience.

University is free in my country.

(And yes, it will be free as in beer, because I won't be going to work, or paying taxes.)

What about the living expenses?

I'll be living off my savings

Sorry, I meant the living expenses of your children, this was related to university costs.

Of course, sorry.

In Australia the government pays students a wage, called Youth Allowance[1], that is something between $268 to $400 every two weeks, depending on circumstances. Combined with a roughly ~10 hour per week part time job, I had no trouble at all putting myself through 5 years of Engineering without any debt. I'm confident my future kids can do the same thing, so I won't need to support them in the same way my parents didn't need to support me (once I went to University at 18)

[1] http://www.humanservices.gov.au/customer/enablers/centrelink...