Lyric discussion by mydreamquest 

Cover art for Smile lyrics by Flickerstick

Lyrically, the drug connotation is clear given how "high" is spelled (i.e. hiiiiiiiiiiigh)

Basically, the lyricist is so wasted, he thinks his roach is his soul mate.

the "ship" is a metaphor for his lungs clearly intoxicated by the green stuff.

Turning a "frown" into a "smile" is the concept of taking a downer drug and optimistically enjoying the, ahem, "hiiiigh*.

Not a complex interpretation here. If you've accidentally eaten two brownies too many, the visuals here are as obvious as a brick falling on your head.

[Edit: misspell.]