The purpose of life, really, is two chocolate doughnuts

In Buddhism, the concept of reincarnation is thus (simplified by my own ignorant hand here): we are spiritual beings in essence and we go through different transformations/rebirths, or samsara, to achieve nirvana - the cessation of 'being', the end of suffering and the desires that perpetuate bondage - which all sentient beings are capable of attaining. There are several levels of spiritual being, and through our actions, or karma (the word literally means 'action'), sentient beings either ripen their spiritual selves or degrade themselves. The aim of our many lives, therefore is to achieve higher levels of spirituality in order to attain nirvana, the point where we are no longer in repetitious samsara.

I wonder what lesson in this lifetime I am meant to learn. I should correct myself: how many lessons I am meant to learn (the plural, not the singular, for surely there are many lessons to learn).

When I was younger, I wanted to do big things, things that had more public impact - like being an environmental lawyer or a women's rights activist. Nowadays I just crave a more comfortable life for myself - I am regressing as a human being. Soon I will be nothing more than a suburban housewife.
"But don't you want to have children?" I hear M.'s voice anxiously asking me. No, it's not the real M. - he's in bed, fast asleep.
"That's not the point, my dear," I answer him back, in my head. "The point is, I will be mired in my daily life and I will no longer be able to attain any higher level of being. Unless I take the children out in a cardboard box and try to sell them for two muffins."
"Right," I hear M. say, sarcastically but still anxiously.
"I mean, of course, I'd never try to exchange my children for two muffins," I say to him, still in my head, but even so, adding under my breath ("But I might for two chocolate doughnuts"). "I'm just saying, I'm worried about what is my purpose in life. Surely it's not just to be your wife and have two children and work like crazy. Surely I'm meant to do something else with my life, too? Something more important?"
"Isn't being with me and having children something important?" M. would say.
"Of course it is. But you're not getting the point," I say.
"Well then, what is the point?" M. says, now teasing.
"I don't know," I say, feeling frustrated at myself.
"Well, if you want to do something 'important', what about writing?" M. asks.
"What about writing?" I ask back.
"Can't you write and be someone important?" M. asks.
"And who's going to publish me?" I ask.
"I would," M. says. He is loyal about my hobbies - blogging, painting and talking the hindleg off a donkey - even if he doesn't always think I am good at them. I know this, that's why I imagine him saying this. I laugh.
"That's very sweet of you. But I think there must be something else I can do," I say to the M. in my head. "Although I'm not sure what."

I know I'm being impatient, that in many senses, I am at the beginning of the rest of my life. There will be opportunities that can only come along with time. But I feel I should think about these things now. Who will I become? What will I be doing?

I can see my attainment of nirvana will be in another eighty-eight lives' time. If I'm lucky.