The reverse of the medal noun phrase
It can be phrased as the reverse of the shield.
The opposite or contrary aspect of a matter or a situation
Working from home allows you to have a flexible schedule, but he reverse of the medal is that you are easily distracted.
That is the biggest or most difficult problem (with the situation being discussed)
Used to say that somebody is in a better or worse situation.
To see, think about or consider someone or something in a subjective or pessimistic way, usually because of bad previous experiences or preconceived notions
Pessimistic view of something
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.