Darn, I feel this way often - I guess this makes me an old curmudgeon but I find Spotify on mobile, and Snapchat, and many other apps, very confusing and hard to use.
Snapchat just has a bad habit of introducing a feature you need to perform a gesture for and only telling you once and nowhere else.
I wouldn't blame your age on it, I just don't think a lot of these popular apps have particularly good design but get by because the service is solid and hits "good enough" for your average (usually non-technical) user.