Meaning of life

[Hobbes' Choice]

"should" can be used in conditional sentences

In case you arrive late please do this and that. =

Should you arrive late please do this and that.

Should is subjuctive mood of shall.

Perhaps the French grammar could provide some further explanation.
Do we have any French grammarians here ?
The Norman conquest, you know.

I love to explore linguistic enigmas, don´t you ?

Should is from shall. It's English, not French.
Should indicates what ought to be in terms of obligation or probability.

[duszek]

Shall indicates future.

It shall rain tomorrow.

If the future is very speculative we use the subjuctive mood:

It should rain tomorrow. (But people prefer to say: it might rain tomorrow.)

The inversion indicates conditionality:

Should it rain tomorrow ...

[Hobbes' Choice]

Shall indicates future.

It shall rain tomorrow.

If the future is very speculative we use the subjuctive mood:

It should rain tomorrow. (But people prefer to say: it might rain tomorrow.)

The inversion indicates conditionality:

Should it rain tomorrow ...

Shall indicates intention.
I shall walk to work tomorrow.
Should indicates obligation
I should walk to work (but probably will not)

[surreptitious57]

Based on what would you figure out the meaning of life? What makes you happy?

There is no meaning to life per se however you can give meaning to your own life
I am not interested in being happy but in being content [ they are not the same ]