I'm exactly the same and this goes for all my hobbies, not just exercise.
Keep going. Slacking off sometimes can be inevitable but just remember to catch up.
Slow progress is still progress. Just go forward u know.Hahaha :)
I am the same way! If I have people to workout with I'm more motivated to stick with it. I currently don't have anyone so I find it hard to motivate myself to workout.
I'm the same way and I've always been that way. I go through phases all the time... Even with the things that have always interested me (music and food. )
I think, for the average person, that pattern is pretty normal. Life gets in the way sometimes. Working out falls into place on some days/weeks, and other times more of an effort is required. I just have to remind myself that I never once regret making time for any extra activity. Motivation is definitely a key role in success when it comes to an exercise regimen. Just keep at it!