Yefim, in contexts like this "life" goes without the definite article. It's either "My life..." or "Life...".

Abstract nouns don't take the definite article unless there modified by an
adjective.

to Uly: Wouldn't it be better to say "Life has never prepared me..."?

@aleh: No, because "never" here doesn't mean никогда не, it means так и не when something doesn't work out the way you feel it was supposed to or the way it was planned to. This form never takes the perfect. For example: "We were supposed to meet in front of the movie theater and he never showed up." here you could never say "has never shown up." In my sentence, life is supposed to prepare you for certain things, and here it field two. So we use "never" instead of "didn't."

Thank you! How would you say then, "Вся жизнь готовила меня к этому"?

My life up till now has prepared me for this. But here it's different because it's an affirmative sentence, not a negative.

You're saying that that the use of perfect is different depending on whether a sentence is affirmative or negative?

Absolutely. The perfect has a lot of nuances and they can all be negated in different ways.

For example: the question "Has she been to Paris" can be negated as: She hasn't been to Paris (...not yet, but she may go one day); She has never been to Paris (...just a fact); She never went to Paris (... she planned to, but never made it); She didn't go to Paris (... she visited several European cities, but Paris wasn't one of them); She never has been to Paris (...hmmm, maybe she should think about going to Paris); just to give you a few examples.

Man! You should post it as a note for everyone to read. I'll try to fathom it. I promise. And I really apreciate it!

It's always a pleasure, Aleh. You can also friend me on VK so you can ask questions whenever you want :-)