"Nie powinieneś myśleć o śmierci."

Translation: You should not think about death.

[maramaxwell05]

This lesson is sinister

[amazingkurwa]

Duolingo stop.

[polechka8]

God damn please stop it

[ellewrobo]

This is just a bunch of bad advice all in a row.

[nerguy_pablo]

Nie myśl o różowej słonia! ;)

[Jellei]

Słoń is masculine, "Nie myśl o różowym słoniu". Or plural: "Nie myśl o różowych słoniach".

[nerguy_pablo]

Znowu dzięki, Jellej :D

[polechka8]

Thx duo!

[Aftellen1887]

Kliknęłam a się nie pojawiło

[Martin95000]

Why not?

[Martin95000]

Think about cookies instead! Not about sugar!

[MattBooguy]

Niech się ludzi myślą o śmierć

[alik1989]

Myśleć is non-reflexive, so the unstressed reflexive pronoun się is misplaced here. You can use the stressed dative-case reflexive pronoun sobie after the subject (ludzie), but that's more of a causal speech filler which doesn't make a lot of difference semantically.

Ludzi is accusative/genitive, but since it's the subject here, it needs to be in the nominative case, which is ludzie.

Myśleć o takes locative, so śmierć should become śmierci.

All in all: Niech ludzie myślą o śmierci.

[dubas90]

I'll try it but the struggle is real.

[Karetchko]

It's 2020. Thinking about death is everyday stuff.