Yep, you gonna die.
I skateboarded as a kid, but quit and then picked up snowboarding about 12 years later. A couple summers ago, I thought I'd pick up a longboard to play around on during the summer.
Bad move. I was way too accustomed to speed on a snowboard. First time on the the longboard I head over to a mild hill and hop on. I'm riding and everything is going awesome. I get to the bottom of the hill and I'm riding it out. I think I'm going slow enough to step off and run it out. Wrong. I step off, make it two, maybe three steps then realize this shit ain't gonna work and tuck and barrel roll it. It felt like I was going super slow but I wasn't. I repeat that scenario two more times before accepting that my concept of speed on a board has been too biased by snowboarding to safely adapt to longboarding. I'm sure I could've made the transition, but I was gonna end up fucking myself up in the process.