I can't really say if by your not putting all your eggs in one basket as per diversification here, you mean like not having to invest on a single coin or its more about having other jobs aside from having some cryptocurrency portfolio.

I think that's the most important in order to be successful in holding. Let's not forget, coins are money and can be swapped to its fiat equivalent. Now, money is how you get satisfy wants/needs and solve issues. You can't do all that depending on a crypto portfolio which your not supposed to touch.

Having another job takes your mind off it and in combination  with other attributes listed above, you might as well be good for the task.