Canadian
If you were born in Canada, you are automatically Canadian for life. Even if you become Canadian, you retain that citizenship, even if you no longer live in Canada. Incidentally, you can also become Canadian if you have a Canadian parent. This even applies, with some restrictions, if you were born outside of Canada.
European
The rules regarding citizenship in European countries are sometimes complicated and they are not the same in all countries of the Union.
The rule of thumb is that you have European citizenship if at least one of your parents also had it.
However, you can lose it, for example if you voluntarily acquire Canadian citizenship.
Dual nationality
There are countries where having more than one nationality is sometimes viewed strangely. Yet, it can happen. A good example is someone whose parents have different nationalities.
In Canada, maintaining another nationality is no problem at all. The country has been accustomed to it for a long time.
In some European countries, the concept of dual nationality is also becoming more normal.
However, it is definitely worth a thorough investigation to see whether you might also have dual nationality.
The rule of thumb is that if you can obtain a passport from a country, you are also a citizen. But you can also be a citizen of a country if you've never held a passport from that country, or if it has long since expired.
Advantages
There are interesting advantages to holding more than one nationality. You're always welcome in that country. After all, you can always come home.
As a citizen, you are entitled to certain consular services. Sometimes this can be important.
As a citizen, you can also pass on this privilege to the next generation.
Furthermore, there are conceivable cases where you could get an easier border crossing somewhere with a particular passport.
Do you know now?
It's absolutely crucial that you know which nationality(ies) you hold. If in doubt, it's a good idea to inquire quickly.
If you inquire in writing with the Consulate, you'll have some proof. However, it often takes a very long time before you hear back.

Two passports can be useful
Dual nationality
How and when do you qualify for two passports? What are the advantages? Are there any disadvantages?
Read here an experience report from someone who had to go through all the steps.
Moving without a passport
Losing your Dutch nationality
If you voluntarily became Canadian, you probably lost your Dutch nationality.
Read here an experience report from someone who found a solution.
Experiences of others
All kinds of considerations
Anyone who's lived in two countries might have some interesting stories. We've gathered a few.
Read here about the different experiences of emigrants who were or were not successful.
On to Canada!
Anyone who visits Canada will be impressed. What a beautiful, spacious, and free country. It's a wonderful place to be.
Quite a few people would like to move to Canada. Emigrate, that is. It's an option for many, and it might be worth exploring.
This website provides you with a lot of background information about the possibility of better considering immigration to Canada.
Take a look at www.menno.ca