Moto2 graduate Smith was thrilled to get straight into QP2 at Losail thanks to his ninth place in third practice, and to be within 0.8 seconds of pacesetter Marc Marquez as he did so.
But the Briton said pulling off that lap had underlined how much of a challenge MotoGP would be.
Asked by AUTOSPORT how his practice achievements on his MotoGP debut ranked alongside other career highs, Smith replied: "It's well up there. It's nowhere near a victory. It's a big achievement.
"To be within a second is something I've always been edging towards. Maybe it was a bit of an adventurous target.
"I didn't realise how hard you had to ride to be within that second. It thought it would come easier than it was. You need to absolutely go wide open to be within a second of these guys.
"It's made me realise that the job's a lot harder than I very first thought.
"Definitely riding 20 laps at that type of intensity... hats off to these guys. It's opened my eyes to MotoGP."
Smith believes his raw pace is not a problem, but that adjusting to the mental demands of motorcycle racing's top level could be tough.
"There's more to come, but it's learning to ride at that intensity and getting your brain to work at that intensity," he explained.
"At the moment, I'm rushing everything. I didn't feel like I had a second to breathe.
"What happens naturally as a rider is that you're able to take it to that intensity but you're able to breathe at every corner, and I think that's where the next step is going to come. It might not come this weekend, but it doesn't take long to sort that out."
- Sports & Recreation