Hi,
I've always wanted play piano.(I played classical guitar before)
Recently, I've got a nice digital piano(yamaha p120s) and trying teach myself to play.
I've finished up the first volume of Thompson in
two weeks and trying to play Czerny.
Casually, I just played through 14th song.
However, my wife, who had lessons when she was a kid, commented that I should play one song for a couple of days and completely master it
until you could even memorize the song.
I took the advice and played a one song until I don't make a mistke and play perfectly.
Well, I felt that it improves certain areas such as finger positioning and also my fingers felt stronger.
The thing is.. It gets so boring!!!...
I also felt that It doesn't improve my sight reading in this way.

The question is should I follow my wife's advice or
anyone have a better idea of practicing?

thanks

She's absolutely right. You should work on a piece, memorize it, and learn to play it properly. But you're not wrong. If you practice a piece that you don't really care for, then it can get boring.

You need to find pieces at your level that you would like to have in your repertoire. Then you won't become bored while practicing it.