i really love singing in the shower.
I do too!  A lot of people like it because the hard surfaces create great acoustics
yes! It kinda makes me feel like i sound better in a shower
The first reports of people singing in the bathroom are from multiple centuries ago
What? That's insane :) I guess singing in a shower isn't so rare
"My Bologna," in the bathroom across from the California Polytechnic State University student radio station where he was DJing at the time. "There's More to Life Than This", the fourth track on Björk's 1993 album "Debut", was recorded live in the toilets of the Milk Bar clubnight, London.
See also.
- Room modes
- Acoustic resonance
- Voice frequency
References.
- Jearl Walker, "The Flying Circus of Physics"
Bathroom singing
Bathroom singing, also known as singing in the bathroom, singing in the bath, or singing in the shower, is a widespread phenomenon. 
Many people sing in the bathroom because the hard wall surfaces, often tiles or wooden panels, and lack of soft furnishings, create an aurally pleasing acoustic environment. The multiple reflections from walls enrich the sound of one's voice. Small dimensions and hard surfaces of a typical bathroom produce various kinds of standing waves, reverberation and echoes, giving the voice "fullness