[GirishSharma643]

The biggest threat is health. The whole world have become helpless in front of Corona. World class medical institution, labs, scientist, colleges were weeping like an orphaned child. Don't think other than health. If we will remain, then we will think and work. For anything else human life needs.

[soultrees]

For inspiration what are some easy problems to solve and then what are some of the more difficult problems to solve on the same path?

[GirishSharma643]

In my personal opinion there is no big issue other than human health. I will repeat - for anything else human life requires.