Two.

I guess it's true when somebody says that you can't have two things at a time.

Some-clever-body.

When you have a 123852247kg thing on your left hand, you can't have another 123852247kg thing on your right hand.

You will break your clavicle and your spine will be a gone case.

So no.

You cannot have long hair and short hair at the same time. You will look like an idiotic moron. (If your hairstylist sucks, that is.)

So no.

You cannot have two friends who at the same time, hates each other. She will talk bad about her and she will talk bad about her and you will get confused and influenced by both sides and you will confuse yourself even more and someday, surely fed up.

So no.

You cannot be in school and in the clinic at the same time even though both events are equally important.

I SAY EQUALLY IMPORTANT.

So it's the choice that makes the difference.