Because I am introspective, analytical, and really value being "genuine"...I struggle with being critical (read any ENFP personality profile, and you can get an idea!). I also grew up in a home where our deeds and motives were constantly critiqued--no doubt with good intentions of helping us see where we excelled and where we needed work--but these facts have accumulated and molded my nature. I tend to have an opinion about everything, but thankfully as I've matured I've learned when it is/isn't appropriate to share.
Being critical doesn't even mean being negative. It means that you have taken the time to weigh the pros and cons/goods and bads/worthiness vs. silliness of any particular act or word. It means that you have assigned weight to everything. It is exhausting to do so. It also points to unspoken pride in my heart.
I try to keep this idea in mind, this idea of not being concerned with the small things. Not inflating the small things by overthinking them.