As people pointed out it is usually moreso outside factors than internal feelings but sometimes feelings can make you feel like the Hulk
-Your posture
If you are having a shitty day you will just close up and shrink inside yourself.
If you are having a pretty decent day you will puff up your chest and stand up tall and might feel like a giant compared to before even though physically you are the same
-Equipment
Shoes. Sometimes even socks make a difference. Then you have clothes. Some clothes (stripes) make people seem taller than they actually are.
-Landscape
I sometimes would stand on top of a little hill when my school would do fire drills and I'd smirk at all the peasants beneath me because I felt tall even though I was just on a tiny hill.
There is something to be said when you are taller than a girl and she is talking with a guy. Then you go up to talk to said girl and you are also taller than the guy and heightmog both of them into oblivion. You know, she knows, AND HE KNOWS her pussy is getting drenched because how Alpha tall you are by comparison.