This one is only honest in retrospect, and only sometimes. Some obstacles taught you something. Others just cost you years, and you'd hand them back tomorrow if there were a desk for that.
The defensible version is narrower. You're thanking the person who kept going, not the thing that made going hard. There's a real difference between crediting the storm and crediting whoever walked through it.
Think of one you're now on the far side of — a job, an illness, a bad stretch you no longer think about daily. You'd have said you couldn't. You did anyway.
That's the part worth thanking.