Anything you tie your well-being to can be taken from you. And will be in the end.

Yeah, you can't not tie your identity to your work to at least some degree, but you can invest in other things, like family and friends, that will soften the blow of losing it.

It’s a lesson in the inevitable consequences of loving something fiercely, be that your own intellect, your spouse, or a child. You may lose any of these things before you die, and the pain will probably be proportional to the love you felt. I don’t think that’s a lesson in why not to allow yourself to love that way at all.

There may be mental pathways that allow for love without attachment. I personally don’t see them yet; perhaps I need to learn more about Zen or Daoism or something. In my unenlightened state, the only way I see to avoid the pain of loss is avoiding love in the first place, which doesn’t look like a good idea.

I'm far from enlightened myself, but meditation certainly has helped me a great deal in this regard. It's not that I don't grieve loss, but it's no longer such a terrifying and identity-destroying affair.