Is it normal to want to do things, but don't

It's hard to get on track with doing activities. Even if it's things I genuinely enjoy and look forward to doing all the time, I just fall out of it and do nothing. Sometimes it happens while I'm doing the activity itself, I just stop midway and do nothing. In the past it used to affect basic things like eating or talking to people, but now I feel like I have a better handle on doing those.