Adolescence /ˌæd

reminder /rɪˈmaɪn.də r / /-dɚ/ noun
2. a reminder of sb/sth
a person or thing which makes you remember a particular person, event or situation
[ + question word ] Alison's story is a reminder of how vulnerable women can be in what is still essentially a man's world.
skill /skɪl/ noun [ C or U ]
an ability to do an activity or job well, especially because you have practised it
Ruth had/possessed great writing skills.
I have no skill at/in sewing.
stage /steɪdʒ/ noun [ C ] PART
1. a part of an activity or a period of development
The project is in its final stages and should be completed by August.
They did the last stage of their journey on foot.
Our marriage is going through a difficult stage at the moment.
Their youngest child is at the stage where she can say individual words but not full sentences.
I'm not tired at the moment but I will need a rest at some stage (= at some time) during the walk.
Andrew spends all his spare time playing with his computer but it's probably just a stage he's going through (= a period of development that will end soon) .
2. in stages
If you do something in stages, you divide the activity into parts and complete each part separately
We're decorating the house in stages so it won't be ready for another couple of months.
3. specialized one of the separate parts of a rocket, each part having its own engine
Once its fuel supply runs out, each stage separates from the main part of the rocket and falls back to Earth.
toddler /ˈtɒd.lə r / /ˈtɑːd.lɚ/ noun [ C ]
a young child, especially one who is learning or has recently learned to walk
transition /trænˈzɪʃ. ə n/ noun [ C or U ]
a change from one form or type to another, or the process by which this happens
The health-care system is in transition at the moment.
There will be an interim government to oversee the transition to democracy.