I had this conversation with someone at work the other day actually, not about me but in general. We were talking about how there's always something you could feel like you weren't ready for, whether it's needing a bigger house, finances or more time... there's always something if you're being really sensible that would stop you trying.
Sometimes you've just got to ignore it all and say stuff it, it's what we want let's just go for it.
My course is still going to take me 4 or 5 years depending on how many credits I squeeze in each year as it's a full degree and I'm doing it part time while working full time.