Sufficient Sufficiency?

Each year I have a similar discussion with myself: 'don't grow so many, courgettes, cucumbers, beans, etc' then I see a different variety I want to try, but don't want to put all my eggs in one basket, so to speak, and continue growing the old favourites. Plus the allure of sowing time, when every packet of seed is considered, and as you know one more won't hurt. I'll never be self sufficient, as I seldom do winter veg, but I have more than a sufficiency in some areas.