My daughter was an awful baby and early toddler. She didn't eat. She didn't sleep. From 5 months to 11 months, she stayed the same weight (which is atypical and makes doctors get very anxious). She didn't even double her weight by her first birthday. Most kids at least triple their weight.
What my daughter was great at was screaming. That shrill "someone is killing me" scream, akin to those in horror movies, for 20 hours per day. I didn't dare even take her for a walk in her stroller because anyone within a mile thought she was being tortured. And she slept for no more than 10-15 minutes at a time. A year and a half of a screaming, anorexic, constantly awake baby was more than either of us good take (even if she was related to us). Thank heavens nothing was seriously wrong her. But there was obviously something wrong with her to act like that for so long. The doctors could never figure it out. Their only advice was to get her to eat more, but when she screamed like you were killing her every time you tried to feed her, it was a losing proposition.
She is still a poor sleeper. The kid is almost 6 years old and gets 8 hours of sleep on a good night. She gave up naps completely at age 2. She gets up in the middle of the night. Of course, she sleeps longer than 10 minutes at a time now (and she no longer screams all day), so it is 1,000x improved from her first year.
Eating has been an ongoing struggle. By the age of 2.5, we gave up feeding therapy. Her first year was beyond awful. She'd eat about 6-8 ounces of formula or breast milk per day total (average is 26 oz for other babies). When we tried to get her to solid food, she refused any baby food. By my calculations, she ate about 250 calories per day. Babies are supposed to eat about 800-1000 calories per day. You can probably ascertain why she didn't gain any weight for 6 months and why we were panicky. If she had been a delightful baby but just had a weak appetite, it probably would have been easier to let it slide. But when she was the crankiest baby ever (wouldn't you if you were perpetually hungry but it hurt to eat?), it signaled that something was up.
Then she was given the "failure to thrive" diagnosis, which has got to be the worst thing you can tell a little baby. You're a failure, and you're not thriving.
We paid our dues early on this kid. Her first year and a half was an utter nightmare, but she has been such a great kid after she started eating and sleeping a bit more. I would have said two years ago that her eating is still really weak, but at least she's happy and doesn't seem to be in pain. Now I'd say her caloric intake is where it should be.
Yes, I still mentally count her calories. Back when she was born, I had to log every speck she drank for the doctor. Which meant I couldn't just breastfeed her. I had to pump and then measure it and give it to her, calculating intake by milliliters (or ounces, but let's not get too ambitious!). After all of that meticulous logging, I still do it, even though it's mentally. On days she crosses 1,000 calories, I do a little jig. By now she's probably supposed to be eating 1,300 calories per day or so (I don't really know, but I know as a 3 year old she was supposed to be eating 1,000 calories).
She's healthy. She's happy. It's been a long, long road to go. And one I never want to repeat. I felt such anguish for her and how I couldn't ever make her feel better. I'm glad she finally turned a corner. It's a long sigh of relief.